A sustainable procedure toward alkyl arylacetates: palladium-catalysed direct carbonylation of benzyl alcohols in organic carbonates

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Feb 082018

A sustainable procedure toward alkyl arylacetates: palladium-catalysed direct carbonylation of benzyl alcohols in organic carbonates

Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC03619A, Communication

Yahui Li, Zechao Wang, Xiao-Feng Wu
A sustainable procedure for the synthesis of various alkyl arylacetates from benzyl alcohols has been developed

A sustainable procedure toward alkyl arylacetates: palladium-catalysed direct carbonylation of benzyl alcohols in organic carbonates

Yahui Li,^a Zechao Wang^a and Xiao-Feng Wu*^a^b

Author affiliations

* Corresponding authors

^a Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock, Germany

^b Department of Chemistry, Zhejiang Sci-Tech University, Xiasha Campus, Hangzhou 310018, People’s Republic of China
E-mail: Xiao-Feng.Wu@catalysis.de

Abstract

A sustainable procedure for the synthesis of various alkyl arylacetates from benzyl alcohols has been developed. With palladium as the catalyst and organic carbonates as the green solvent and in situ activator, benzyl alcohols were carbonylated in an efficient manner without any halogen additives.

Ethyl 2-phenylacetate

1H NMR (300 MHz, Chloroform-d) δ 7.32 – 7.08 (m, 5H), 4.08 (q, J = 7.1 Hz, 2H), 3.54 (s, 2H), 1.18 (t, J = 7.1 Hz, 3H).

13C NMR (75 MHz, CDCl3) δ 171.61, 134.17, 129.24, 128.54, 127.03, 60.85, 41.45, 14.18.

//////http://pubs.rsc.org/en/Content/ArticleLanding/2018/GC/C7GC03619A?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Bio-derived production of cinnamyl alcohol via a three step biocatalytic cascade and metabolic engineering

PROCESS, spectroscopy, SYNTHESIS, Uncategorized Comments Off

Jan 122018

Bio-derived production of cinnamyl alcohol via a three step biocatalytic cascade and metabolic engineering

Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC03325G, Paper

Evaldas Klumbys, Ziga Zebec, Nicholas J. Weise, Nicholas J. Turner, Nigel S. Scrutton
Cascade biocatalysis and metabolic engineering provide routes to cinnamyl alcohol.

Bio-derived production of cinnamyl alcohol via a three step biocatalytic cascade and metabolic engineering

Evaldas Klumbys,^a Ziga Zebec,^a Nicholas J. Weise,^a Nicholas J. Turner^a and Nigel S. Scrutton*^a

* Corresponding authors

^a Manchester Institute of Biotechnology (MIB), School of Chemistry, The University of Manchester, 131 Princess Street, Manchester, UK
E-mail:nigel.scrutton@manchester.ac.uk

Evaldas Klumbys

Image result for Nigel Scrutton

Prof Nigel ScruttonScD, FRSC, FRSB

Professor of Enzymology and Biophysical Chemistry

Email:
Nigel.Scrutton@manchester.ac.uk

Phone: +44 (0) 161 306 5152

Full contact details

ORCID: 0000-0002-4182-3500

Abstract

The construction of biocatalytic cascades for the production of chemical precursors is fast becoming one of the most efficient approaches to multi-step synthesis in modern chemistry. However, despite the use of low solvent systems and renewably resourced catalysts in reported examples, many cascades are still dependent on petrochemical starting materials, which as of yet cannot be accessed in a sustainable fashion. Herein, we report the production of the versatile chemical building block cinnamyl alcohol from the primary metabolite and the fermentation product L-phenylalanine. Through the combination of three biocatalyst classes (phenylalanine ammonia lyase, carboxylic acid reductase and alcohol dehydrogenase) the target compound could be obtained in high purity, demonstrable at the 100 mg scale and achieving 53% yield using ambient temperature and pressure in an aqueous solution. This system represents a synthetic strategy in which all components present at time zero are biogenic and thus minimises damage to the environment. Furthermore we extend this biocatalytic cascade by its inclusion in an L-phenylalanine overproducing strain of Escherichia coli. This metabolically engineered strain produces cinnamyl alcohol in mineral media using glycerol and glucose as the carbon sources. This study demonstrates the potential to establish green routes to the synthesis of cinnamyl alcohol from a waste stream such as glycerol derived, for example, from lipase treated biodiesel.

(R)-3-amino-3-(3-fluorophenyl)propanoic acid (1c) 1H NMR (CDCl3): δ 7.16-7.31 (m, 5H, ArH), 6.50-6.54 (d, 1H, J = 16 Hz, C=CH), 6.23-6.30 (dt, 1H, J = 16, 8 Hz, C=CHCH2 ), 4.21-4.23 (dd, 2H, J = 8, 4 Hz, C=CHCH2); 13C NMR (CDCl3): 136.70, 131.09, 128.60, 128.54, 127.69, 126.48, 63.65.

////////////cinnamyl alcohol, biocatalytic, metabolic engineering

Stable and reusable nanoscale Fe2O3-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides

organic chemistry, spectroscopy, SYNTHESIS Comments Off

Dec 292017

Stable and reusable nanoscale Fe2O3-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides

Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC02627G, Paper

Kathiravan Murugesan, Thirusangumurugan Senthamarai, Manzar Sohail, Muhammad Sharif, Narayana V. Kalevaru, Rajenahally V. Jagadeesh
Nanoscale Fe₂O₃-catalyzed environmentally benign synthesis of nitriles and amides has been performed from easily accessible aldehydes and ammonia using O₂.

http://pubs.rsc.org/en/Content/ArticleLanding/2018/GC/C7GC02627G?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Stable and reusable nanoscale Fe₂O₃-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides

Kathiravan Murugesan,^a Thirusangumurugan Senthamarai,^a Manzar Sohail,^b Muhammad Sharif,^b Narayana V. Kalevaru^a and Rajenahally V. Jagadeesh*^a

Author affiliations

* Corresponding authors

^a Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
E-mail:Jagadeesh.Rajenahally@catalysis.de

^b The Center of Research Excellence in Nanotechnology (CENT) and Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia

Abstract

The sustainable introduction of nitrogen moieties in the form of nitrile or amide groups in functionalized molecules is of fundamental interest because nitrogen-containing motifs are found in a large number of life science molecules, natural products and materials. Hence, the synthesis and functionalization of nitriles and amides from easily available starting materials using cost-effective catalysts and green reagents is highly desired. In this regard, herein we report the nanoscale iron oxide-catalyzed environmentally benign synthesis of nitriles and primary amides from aldehydes and aqueous ammonia in the presence of 1 bar O₂ or air. Under mild reaction conditions, this iron-catalyzed aerobic oxidation process proceeds to synthesise functionalized and structurally diverse aromatic, aliphatic and heterocyclic nitriles. Additionally, applying this iron-based protocol, primary amides have also been prepared in a water medium.

1H NMR (300 MHz, Chloroform-d) δ 7.17 – 6.96 (m, 2H), 6.93 – 6.70 (m, 1H), 4.33 – 4.11 (m, 4H). 13C NMR (75 MHz, Chloroform-d) δ 147.75 , 143.80 , 125.87 , 121.21 , 118.91 , 118.25 , 104.38 , 64.59 , 64.12 . Off white solid

cas 19102-07-9

1,4-Benzodioxan-6-carbonitrile (8CI)
2,3-Dihydro-1,4-benzodioxin-6-carbonitrile
1-(2,3-Dihydrobenzo[b][1,4]dioxin-6-yl)nitrile

Melting Point, °C
105 – 106 Tetrahedron, 2015, vol. 71, 29, p. 4883 – 4887

Melting Point, °C

105 – 106

Tetrahedron, 2015, vol. 71, 29, p. 4883 – 4887

NMR PREDICTS

1H NMR

13C NMR PREDICT

More…………….

Journal of the American Chemical Society, 2001, vol. 123, 49, p. 12202 – 12206

More………….

RSC Advances, 2013, vol. 3, 44, p. 22389 – 22396

http://www.rsc.org/suppdata/ra/c3/c3ra44386h/c3ra44386h.pdf

MORE……..

Organic Letters, 2017, vol. 19, 12, p. 3095 – 3098

http://pubs.acs.org/doi/suppl/10.1021/acs.orglett.7b01199/suppl_file/ol7b01199_si_001.pdf

2,3-Dihydrobenzo[b][1,4]dioxine-6-carbonitrile (Scheme 1, 2n) According to the general procedure A, the reaction of 1n (0.20 mmol), zinc cyanide (2.0 equiv), PCyPh2 (0.20 equiv) and Pd(OAc)2 (0.05 equiv) in dioxane (0.25 M) for 16 h at 150 °C, afforded after work-up and chromatography the title compound in 75% yield (24.2 mg). White solid. 1H NMR (500 MHz, CDCl3) δ 7.17-7.11 (m, 2H), 6.91 (d, J = 8.1 Hz, 1H), 4.32-4.31 (m, 2H), 4.30- 4.26 (m, 2H). 13C NMR (125 MHz, CDCl3) δ 147.84, 143.91, 126.04, 121.37, 119.01, 118.37, 104.62, 64.71, 64.24.

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Sulfurative self-condensation of ketones and elemental sulfur: a three-component access to thiophenes catalyzed by aniline acid-base conjugate pairs

green chemistry, organic chemistry, PROCESS, spectroscopy, SYNTHESIS Comments Off

Dec 282017

Sulfurative self-condensation of ketones and elemental sulfur: a three-component access to thiophenes catalyzed by aniline acid-base conjugate pairs

Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC03437G, Communication

Thanh Binh Nguyen, Pascal Retailleau
An aniline/acid-catalyzed method for constructing thiophenes 2 from inexpensive ketones 1 and elemental sulfur is reported.

Sulfurative self-condensation of ketones and elemental sulfur: a three-component access to thiophenes catalyzed by aniline acid–base conjugate pairs

Thanh Binh Nguyen*^a and Pascal Retailleau^a

Author affiliations

* Corresponding authors

^a Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Sud, Université Paris-Saclay, 1, av de la Terrasse, 91198 Gif-sur-Yvette, France
E-mail: nguyen@icsn.cnrs-gif.fr

Abstract

A sulfurative self-condensation method for constructing thiophenes 2 by a reaction between ketones 1 and elemental sulfur is reported. This reaction, which is catalyzed by anilines and their salts with strong acids, starts from readily available and inexpensive materials, and releases only water as a by-product.

2,4-Di-p-tolylthiophene (2b)2

2 M. Arisawa, T. Ichikawa, and M. Yamaguchi, Chem. Commun. 2015, 51, 8821

Eluent heptane:toluene 9:1. 190 mg, 72%.

1 H NMR (300 MHz, CDCl3) δ 7.60-7.54 (m, 5H), 7.34 (s, 1H), 7.27-7.23 (m, 4H), 2.42 (s, 6H).

13C NMR (75 MHz, CDCl3) δ 145.3, 143.3, 137.8, 137.2, 133.5, 131.9, 129.9, 129.8, 126.5, 126.0, 122.1, 118.9, 21.5, 21.5.

Binh Thanh Nguyen

CV Binh Nguyen

CNRS Research Associate CR1 ( ORCID , ResearchGate )

ICSN-CNRS Bât. 27

1, avenue de la Terrasse

91190 Gif-sur-Yvette France

thanh-binh.nguyen_at_cnrs.fr

+33 1 69 82 45 49

Education and work experience2015: Habilitation to Direct Research (HDR)

2011 – present: CNRS research associate at ICSN – Paris-Saclay University

2009 – 2011: Post-doctoral Fellow at ICSN (Dr. Françoise Guéritte and Dr. Qian Wang)

2003 – 2006: Ph.D. student at the UCO2M Organic Synthesis Laboratory (University of Maine, Le Mans, France, Dr. Gilles Dujardin, Dr. Arnaud Martel, Professor Robert Dhal)

Research Interests

Green chemistry (Atom, step and redox economic transformation), green synthetic tools: O2, S8, photochemistry, iron catalyst

Elemental sulfur as a synthetic tool (building block, oxidant, reductant, catalyst)

Iron-sulfur catalysts

Heterocycle synthesis

Scientific Communications

47 publications

Selected recent publications ( complete list )

[1] Adv. Synth. Catal. 2017 , 359 , 1106.

[2] Asian J. Org. Chem. 2017 , 6 , 477.

[3] Org. Lett. 2016 , 18 , 2177.

[4] Org. Process Res. Dev. 2016 , 20 , 319.

[5] Angew. Chem. Int. Ed. 2014 , 53 , 13808.

[6] J. Am. Chem. Soc. 2013 , 135 , 118.

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HMF in multicomponent reactions: utilization of 5-hydroxymethylfurfural (HMF) in the Biginelli reaction

organic chemistry, spectroscopy, SYNTHESIS Comments Off

Dec 212017

HMF in multicomponent reactions: utilization of 5-hydroxymethylfurfural (HMF) in the Biginelli reaction

Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC03425C, Paper

Weigang Fan, Yves Queneau, Florence Popowycz
The use of the renewable platform molecule 5-hydroxymethylfurfural (HMF) in the multi-component Biginelli reaction has been investigated.

HMF in multicomponent reactions: utilization of 5-hydroxymethylfurfural (HMF) in the Biginelli reaction

Weigang Fan,^a Yves Queneau*^a and Florence Popowycz*^a

http://pubs.rsc.org/en/Content/ArticleLanding/2018/GC/C7GC03425C?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

* Corresponding authors

^a Université de Lyon, INSA Lyon, ICBMS, Equipe Chimie Organique et Bioorganique, UMR 5246 CNRS, Université Lyon 1, CPE Lyon, Bâtiment Jules Verne, 20 Avenue Albert Einstein, F-69621 Villeurbanne Cedex, France
E-mail: yves.queneau@insa-lyon.fr, florence.popowycz@insa-lyon.fr

Abstract

The use of the renewable platform molecule 5-hydroxymethylfurfural (HMF) in the multi-component Biginelli reaction has been investigated. Multicomponent reactions (MCR) using HMF offer straightforward access to novel fine chemicals. However, the peculiar reactivity and lower stability of HMF have limited its use in such strategies. In this paper, we report our results on the use of HMF in 3-component Biginelli reactions, leading in one single step to a series of functionalized dihydropyrimidinones obtained in moderate to good yields, with a broad substrate scope of 1,3-dicarbonyl compounds and urea building blocks. This is the first report on the use of HMF in this reaction. The CH₂OH motif found in HMF provides useful functionalization for the target molecules, which cannot be offered by simpler aldehydes such as furfural.

5-Acetyl-4-[5’-(hydroxymethyl)furan-2’-yl]-6-methyl-3,4-dihydropyrimidin-2(1H)-one (4a):

Reaction time: 8 h; Global yield: 86%; (78% yield after simple filtration + additional 8% yield after purification of the filtrate by column chromatography).

1H NMR (400 MHz, DMSO-d6) δ 9.22 (d, 1H, J = 1.2 Hz, H1), 7.88 (dd, 1H, J = 3.4, 1.2 Hz, H3), 6.16 (d, 1H, J = 3.1 Hz, H4’), 6.03 (d, 1H, J = 3.1 Hz, H3’), 5.27 (d, 1H, J = 3.4 Hz, H4), 5.18 (t, 1H, J = 5.6 Hz, OH), 4.33 (d, 2H, J = 5.6 Hz, CH2), 2.25 (s, 3H, CH3-C6), 2.17 (s, 3H, CH3CO).

13C NMR (100 MHz, DMSO-d6) δ 193.9 (COCH3), 155.1, 154.9 (C2’, C5’), 152.4 (C2), 149.0 (C6), 107.7 (C4’), 107.1 (C5), 106.3 (C3’), 55.7 (CH2OH), 47.9 (C4), 30.0 (CH3CO), 19.0 (CH3-C6).

HRMS (ESI) m/z: Calcd for [M+Na]+ C12H14N2NaO4 273.0846; Found 273.0850.

Weigang Fan

Research experience

Sep 2015–Mar 2017

Doctorant

Institut National des Sciences Appliquées de Lyon · Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS – UMR 5246)

France · Lyon

Florence POPOWYCZ

Université de Lyon, INSA Lyon, ICBMS, Equipe Chimie Organique et Bioorganique, UMR 5246 CNRS, Université Lyon 1, CPE Lyon, Bâtiment Jules Verne, 20 Avenue Albert Einstein, F-69621 Villeurbanne Cedex, France
E-mail: florence.popowycz@insa-lyon.fr

Yves QUENEAU

CNRS Research Director chez ICBMS INSA Lyon Univ Lyon – Carbohydrate Chemistry

ICBMS INSA Lyon University of Lyon

///////////////HMF, multicomponent reactions, 5-hydroxymethylfurfural, Biginelli reaction

Synthesis of highly functional carbamates through ring-opening of cyclic carbonates with unprotected α-amino acids in water

organic chemistry, spectroscopy, SYNTHESIS Comments Off

Dec 202017

Synthesis of highly functional carbamates through ring-opening of cyclic carbonates with unprotected [small alpha]-amino acids in water

Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC02862H, Paper

Peter Olsen, Michael Oschmann, Eric V. Johnston, Bjorn Akermark
Ring opening of cyclic carbonates with unprotected amino acids in water – a route to highly functional carbamates.

Synthesis of highly functional carbamates through ring-opening of cyclic carbonates with unprotected α-amino acids in water

Peter Olsén,*^a Michael Oschmann,^a Eric V. Johnston*^a and Björn Åkermark*^a

Author affiliations

*Corresponding authors

^aDepartment of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE 106 91, Stockholm, Sweden
E-mail: peter.olsen@su.se, eric@sigridthx.com, bjorn.akermark@su.se

Abstract

The present work shows that it is possible to ring-open cyclic carbonates with unprotected amino acids in water. Fine tuning of the reaction parameters made it possible to suppress the degree of hydrolysis in relation to aminolysis. This enabled the synthesis of functionally dense carbamates containing alkenes, carboxylic acids, alcohols and thiols after short reaction times at room temperature. When Glycine was used as the nucleophile in the ring-opening with four different five membered cyclic carbonates, containing a plethora of functional groups, the corresponding carbamates could be obtained in excellent yields (>90%) without the need for any further purification. Furthermore, the orthogonality of the transformation was explored through ring-opening of divinylenecarbonate with unprotected amino acids equipped with nucleophilic side chains, such as serine and cysteine. In these cases the reaction selectively produced the desired carbamate, in 70 and 50% yield respectively. The synthetic design provides an inexpensive and scalable protocol towards highly functionalized building blocks that are envisioned to find applications in both the small and macromolecular arena.

link http://pubs.rsc.org/en/Content/ArticleLanding/2018/GC/C7GC02862H?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Affiliation

Stockholm University

Location

Stockholm, Sweden

Department

Department of Organic Chemistry

Position

PostDoc Position

Research experience

Jun 2010–Feb 2016

PhD Student

KTH Royal Institute of Technology · Department of Fibre and Polymer Technology

Sweden · Stockholm

Björn Åkermark

Education

Jan 1962–Jun 1967

KTH Royal Institute of Technology

Organic Chemistry and Catalysis · PhD

Sweden · Stockholm

Awards & achievements

Jun 2009

Award: Bror Holmberg Medal, Swedish Chemical Society
Feb 2009

Award: Ulla and Stig Holmquists Prize, Uppsala University
Oct 1997

Award: Dr hc, University D´Aix-Marseille
Oct 1991

Award: KTH Prize for Excellence in Teaching
Oct 1978

Award: Arrhenius Medal, Swedish Chemical Society
Aug 1977

Scholarship: Zorn Fellowship, Swden America Foundation
Nov 1976

Award: Letterstedt Award, Roy Swed. Acad. of Science

Dr. Eric Johnston, Ph.D.

Chief Technology Officer

Dr. Eric V. Johnston obtained his Master of Science degree in 2008 at the Department of Organic Chemistry, Stockholm University, Sweden. In the same year, he started his graduate studies under the supervision of Prof. Jan-Erling Bäckvall. During his PhD, he worked on the development of new homogeneous and heterogeneous transition-metal catalysts.

After receiving his PhD in 2012, he joined Prof. Samuel J. Danishefskys research group at Memorial Sloan-Kettering Cancer Center, New York, USA as a postdoctoral fellow supported by The Swedish Research Council. Here he was engaged in the total chemical synthesis of glycolsylated proteins that play important roles in modern cancer treatment.

In 2014 he returned to the Department of Organic Chemistry at Stockholm University to establish his own group. The goal of his research is to contribute new advances to the strategy and methodology for the preparation of synthetic macromolecules such as proteins, glycopeptides, sequence and length-controlled polymers. He is also a Co-Supervisor for Prof. Björn Åkermarks research group, which aims at studying and developing new homogeneous, as well as heterogeneous, water oxidation catalysts.

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A practical synthesis of 2,3-dihydro-1,5-benzothiazepines

spectroscopy, SYNTHESIS Comments Off

Dec 082017

A practical synthesis of 2,3-dihydro-1,5-benzothiazepines

Green Chem., 2017, 19,5703-5707
DOI: 10.1039/C7GC02097J, Paper

Domenico C. M. Albanese, Nicoletta Gaggero, Meng Fei
Hexafluoro-2-propanol as the solvent allows a catalyst free domino approach to 2,3-dihydro-1,5-benzothiazepines in up to 98% yield.

A practical synthesis of 2,3-dihydro-1,5-benzothiazepines

Domenico C. M. Albanese,^a Nicoletta Gaggero*^b and Meng Fei^b

*Corresponding authors

^aDepartment of Chemistry, Università degli Studi di Milano, via C. Golgi 19, Milano, Italy

^bDepartment of Pharmaceutical Sciences, Università degli Studi di Milano, via L. Mangiagalli 25, Milano, Italy
E-mail:nicoletta.gaggero@unimi.it

Domenico C. M. Albanese

University of Milan

LocationMilano, Italy

DepartmentDepartment of Chemistry

Positionassociate professor

Domenico Albanese received his Ph.D. degree in 1993 with Prof. Dario Landini working on phase transfer catalysis. After short stays at Imperial College London and the Technical University of Denmark, he gained a permanent position at the Università degli Studi di Milano, where he was appointed associate professor in 2008. His research interests include novel developments of phase-transfer catalysis, green chemistry and the development of new environmentally friendly antifouling agents.

University of Milan

image file: c4ra11206g-p2.tif

Nicoletta Gaggero

Nicoletta Gaggero received her Ph.D. degree in 1992 working on stereoselective reactions with natural proteins, enzymes and models of enzymes. After working at the Laboratoire de Chimie de Coordination du CNRS of Toulouse, she obtained a permanent position at the Università degli Studi di Milano. Her research interests cover the field of biocatalysis and asymmetric synthesis.

Abstract

2,3-Dihydro-1,5-benzothiazepines have been obtained through a domino process involving a Michael addition of 2-aminothiophenols to chalcones, followed by in situ cyclization. Up to 98% chemical yields have been obtained at room temperature under essentially neutral conditions by using hexafluoro-2-propanol as an efficient medium.

http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC02097J?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

2,4-Diphenyl-2,3-dihydro-1,5-benzothiazepine (4a)

Yellow solid; mp 114-116 C [lit.1 , 114-115 °C], AcOEt/PE 1:9. 1H NMR (300 MHz, CDCl3,): 3.07 (t, J = 12.6 Hz, 1 H), 3.32 (dd, J = 4.7, 13.1 Hz, 1 H), 4.99 (dd, J = 4.5, 12.0 Hz, 1 H), 7.12-7.17 (m, 1 H), 7.25-7.30 (m, 5 H), 7.44-7.51 (m, 4 H), 7.62 (d, J = 6.1 Hz, 2 H), 8.06 (d, J = 7.5 Hz, 2 H). Isolated Yield: 339 mg, 86%.

2-(4-Hydroxyphenyl)-4-phenyl-2,3-dihydro-1,5-benzothiazepine (4e)

Light brown solid; mp 131-134 °C. AcOEt/PE 40:60.

1H NMR (CDCl3, 300 MHz):  = 3.01 (t, J = 12.7 Hz, 1 H), 3.28 (dd, J = 4.8, 12.9 Hz, 1 H), 4.95 (dd, J = 4.7, 12.5 Hz, 1 H), 5.10 (bs, 1 H), 6.76 (d, J = 8.5 Hz, 2 H), 7.18-7.21 (m, 3 H), 7.35 (d, J = 8.5 Hz, 1 H), 7.46- 7.55 (m, 4 H), 7.63 (dd, J =1.5, 7.7 Hz, 1 H), 8.06 (m, 2 H).

13C NMR (CDCl3, 75 MHz): 37.99 (CH2), 60.07 (CH), 115.53 (CH), 123.08 (C), 127.40 (CH), 128.79 (CH), 131.17 (CH), 136.54 (C), 141.59 (C), 155.24 (C). IR (KBr): 1599, 2921, 3350 cm-1 .

MS (ESI): m/z= 332.24 (MH)+ .

Anal. Calcd. for C21H17NOS: C, 76.10; H, 5.17; N, 4.23, found: C, 76.21; H, 5.15; N, 4.24.

Isolated Yield: 360 mg, 87%.

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‘

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This is a compilation for educational purposes only. P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

Persulfurated Coronene: A New Generation of “Sulflower”

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Dec 062017

2073844-77-4

C₂₄ S_{12, 673.04}

Coroneno[1,12-cd:2,3-c‘d‘:4,5-c”d”:6,7-c”’d”’:8,9-c””d””:10,11-c””’d””’]hexakis[1,2]dithiole

A persulfurated coronene, a molecule dubbed a “sulflower” for its resemblance to a sunflower, bloomed this year. It’s the first fully sulfur-substituted polycyclic aromatic hydrocarbon and only the second member of a new class of circular heterocyclic carbon sulfide compounds, after the synthesis of octathio[8]circulene a decade ago.

Chemists hope to create other class members, including the simplest one, persulfurated benzene, for use in battery cathodes and other electronic materials.

A team led by Xinliang Feng of Dresden University of Technology and Klaus Müllen of the Max Planck Institute for Polymer Research created the sulflower (J. Am. Chem. Soc. 2017, DOI: 10.1021/jacs.6b12630).

http://pubs.acs.org/doi/abs/10.1021/jacs.6b12630

Synthesis of persulfuratedcoronene (5, PSC)

5 (82 mg) as dark red solid in 61% yield. HR-MS (HR-MALDI-TOF) m/z: Calcd. for C24S12: 671.6629; Found 671.6648 [M]+; Elem. Anal. calcd. for C24S12: C, 42.83; S, 57.17. Found: C, 42.87; S, 57.13.

Persulfurated Coronene: A New Generation of “Sulflower”

Renhao Dong^†, Martin Pfeffermann^§, Dmitry Skidin^‡, Faxing Wang^†, Yubin Fu^†, Akimitsu Narita^§, Matteo Tommasini^∥, Francesca Moresco^‡

, Gianaurelio Cuniberti^‡

, Reinhard Berger^†, Klaus Müllen^*^§

, and Xinliang Feng^*^†

^† Department of Chemistry and Food Chemistry, Center for Advancing Electronics Dresden, Technische Universität Dresden, 01062 Dresden, Germany

^§ Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany

^‡ Institute for Materials Science, Max Bergmann Center of Biomaterials, and Center for Advancing Electronics Dresden, TU Dresden, 01069 Dresden, Germany

^∥ Dipartimento di Chimica, Materiali ed Ingegneria Chimica ‘G. Natta’, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy

J. Am. Chem. Soc., 2017, 139 (6), pp 2168–2171

DOI: 10.1021/jacs.6b12630

Publication Date (Web): January 27, 2017

*muellen@mpip-mainz.mpg.de, *xinliang.feng@tu-dresden.de

We report the first synthesis of a persulfurated polycyclic aromatic hydrocarbon (PAH) as a next-generation “sulflower.” In this novel PAH, disulfide units establish an all-sulfur periphery around a coronene core. The structure, electronic properties, and redox behavior were investigated by microscopic, spectroscopic and electrochemical methods and supported by density functional theory. The sulfur-rich character of persulfurated coronene renders it a promising cathode material for lithium–sulfur batteries, displaying a high capacity of 520 mAh g^–1 after 120 cycles at 0.6 C with a high-capacity retention of 90%

Renhao Dong

Image result for Renhao Dong DRESDEN

Research Group Leader

Renhao received his PhD in Physical Chemistry from Shandong University in 2013. Since 01/2017, he is a research group leader at the Chair for Molecular Functional Materials in TUD. His current research interest focuses on synthesis of organic 2D crystals (2D polymers/COFs/MOFs) and their applications in electronics and energy technology.

Contact

Phone: +49 – 351 / 463-40401 or -34932
Email: renhao.dong@tu-dresden.de

Prof. Xinliang Feng

Work Biography:

This is a professorship in the context of the cluster of excellence cfaed.

Xinliang Feng received his Bachelor’s degree in analytic chemistry in 2001 and Master’s degree in organic chemistry in 2004. Then he joined Prof. Klaus Müllen’s group at the Max Planck Institute for Polymer Research for PhD thesis, where he obtained his PhD degree in April 2008. In December 2007 he was appointed as a group leader at the Max-Planck Institute for Polymer Research and in 2012 he became a distinguished group leader at the Max-Planck Institute for Polymer Research.

His current scientific interests include graphene, two-dimensional nanomaterials, organic conjugated materials, and carbon-rich molecules and materials for electronic and energy-related applications. He has published more than 370 research articles which have attracted more than 25000 citations with H-index of 75.

He has been awarded several prestigious prizes such as IUPAC Prize for Young Chemists (2009), Finalist of 3rd European Young Chemist Award, European Research Council (ERC) Starting Grant Award (2012), Journal of Materials Chemistry Lectureship Award (2013), ChemComm Emerging Investigator Lectureship (2014), Highly Cited Researcher (Thomson Reuters, 2014, 2015 and 2016), Fellow of the Royal Society of Chemistry (FRSC, 2014). He is an Advisory Board Member for Advanced Materials, Journal of Materials Chemistry A, ChemNanoMat, Energy Storage Materials, Small Methods and Chemistry -An Asian Journal. He is also one of the Deputy Leaders for European communitys pilot project Graphene Flagship, Head of ESF Young Research Group “Graphene Center Dresden”, and Working Package Leader of WP Functional Foams & Coatings of GRAPHENE FLAGSHIP.

Academic Employment

12/2007-12/2012: Group Leader, Max Planck Institute for Polymer Research in Mainz, Germany
06/2010: Director of the Institute of Advanced Organic Materials, Shanghai Jiao Tong University
03/2011: Distinguished Adjunct Professorship in Shanghai Jiao Tong University, Chin
12/2012-07/2014: Distinguished Group Leader, Max Planck Institute for Polymer Research in Mainz, Germany
08/2014: W3 Chair Professor, Technische Universität Dresden, Germany

Honors and Duties

Marie Currie Fellowship (2005-2006)
Chinese Government Award for Outstanding Self-financed Students (2008)
IUPAC Prize for Young Chemists (2009)
Finalist of 3rd European Young Chemist Award (2010)
ISE (International Society of Electrochemistry) Young Investigator Award (2011)
Adjunct Professorship, China University of Geosciences (Wuhan) (2011)
Deputy Leader of one of the ten European representatives of the European community’s pilot project GRAPHENE FLAGSHIP (2012)
EU FET Young Explorer (2012)
ERC Starting Grant Award (2012)
Advisory Board Member for Advanced Materials (2013)
Journal of Materials Chemistry Lectureship Award (2013)
Advisory Board Member for Journal of Materials Chemistry A (2014)
Editorial Board Member of Chemistry – An Asian Journal (2014)
ChemComm Emerging Investigator Lectureship (2014)
Highly Cited Researcher (Thomson Reuters, 2014)
Fellow of the Royal Society of Chemistry (2014)
Highly Cited Researcher (Chemistry and Materials Science) (2015)
International Advisory Board of Energy Storage Materials (2015)
International Advisory Board of ChemNanoMat (2015)
Highly Cited Researcher (Chemistry and Materials Science, Thomson Reuters) (2016)
Head of ESF Young Research Group “Graphene Center Dresden” (2016)
Working Package Leader of WP Functional Foams & Coatings of GRAPHENE FLAGSHIP (2016)
International Advisory Board of Small Methods (2016)
Path Leader of 2.5D path within the cluster of excellence CFAED (2016)
ERC Proof-of-Concept Project Award (2017)
Small Young Innovator Award (2017)
Hamburg Science Award (2017)

Referee for:

Nature, Science, Nature Materials, Nature Nanotechnology, Nature Chemistry, Journal of the American Chemical Society, Angewandte Chemie International Edition, Nano Letters, Advanced Materials, Chemical Society Reviews, ACS Nano, Small, Chemical Communications, Chemistry of Materials, Organic Letters, Journal of the Organic Chemistry, Chemistry – A European Journal, ChemSusChem, ChemPhysChem, Macromolecular Rapid Communications, Journal of Material Chemistry, New Journal of Chemistry, Chemistry – An Asian Journal, ACS Applied Materials & Interfaces, Energy & Environmental Science, Organic Electronics and so on

Referee for research grants in NSF, US Department of Energy, ESF, ISF and Fondazione Cariparo and Fondazione CariModena.

Publications

Click to open publications list

Contact (Secretariat)

Phone: +49 351 / 463-43251
Fax: +49 351 / 463-43268
Email: sabine.strecker@tu-dresden.de

Klaus Müllen
Max-Planck-Institute for Polymer Research, Mainz, 55128, Germany

Research into energy technologies and electronic devices is strongly governed by the available materials. We introduce a synthetic route to graphenes which is based upon the cyclodehydrogenation (“graphitization”) of well-defined dendritic (3D) polyphenylene precursors. This approach is superior to physical methods of graphene formation such as chemical vapour deposition or exfoliation in terms of its (i) size and shape control, (ii) structural perfection, and (iii) processability (solution, melt, and even gas phase). The most convincing case is the synthesis of graphene nanoribbons under surface immobilization and in-situ control by scanning tunnelling microscopy.
Columnar superstructures assembled from these nanographene discs serve as charge transport channels in electronic devices. Field-effect transistors (FETs), solar cells, and sensors are described as examples.
Upon pyrolysis in confining geometries or “carbomesophases”, the above carbon-rich 2D- and 3D- macromolecules transform into unprecedented carbon materials and their carbon-metal nanocomposites. Exciting applications are shown for energy technologies such as battery cells and fuel cells. In the latter case, nitrogen-containing graphenes serve as catalysts for oxygen reduction whose efficiency is superior to that of platinum.

Müllen, K., Rabe, J.R., Acc. Chem. Res. 2008, 41, (4), 511-520;
Wang, X., Zhi, L., Müllen, K. Nano. Lett. 2008, 8, 323-327;
Feng, X.; Chandrasekhar, N.; Su, H. B.; Müllen, K., Nano. Lett. 2008, 8, 4259.;
Pang, S.; Tsao, H. N.; Feng, X.; Müllen, K., Adv. Mater. 2009, 31, 3488;
Feng, X., Marcon, V., Pisula, W., Hansen, M.R., Kirkpatrick, I., Müllen, K., Nature Mater. 2009, 8, 421;
Cai, J., Ruffieux, P., Jaafar, R., Bieri, M., Braun, T., Blankenburg, S., Muoth, M., Seitsonen, A. P., Saleh, M., Feng, X., Müllen, K., Fasel, R., Nature 2010, 466, 470-473;
Yang, S., Feng, X., Zhi, L., Cao, Q., Maier, J., Müllen, K., Adv. Mater. 2010, 22, 838; Liu, R., Wu, D., Feng, X., Müllen, K., Angew. Chem. Int. Ed. 2010, 49, 2565;
Käfer, D., Bashir, A., Dou, X., Witte, G., Müllen, K., Wöll, C., Adv. Mater. 2010, 22, 384;
Diez-Perez, I., Li, Z., Hihath, J., Li, J., Zhang, C., X., Zang, L., Dai, Y., Heng, X., Müllen, K., Tao, N. J. Nature Commun. 2010, DOI: 10.1038.

Prof. Dr. Klaus Müllen
joined the Max-Planck-Society in 1989 as one of the directors of the Max-Planck Institute for Polymer Research. He obtained a Diplom-Chemiker degree at the University of Cologne in 1969 after work with Professor E. Vogel. His Ph.D. degree was granted by the University of Basel, Switzerland, in 1972 where he undertook research with Professor F. Gerson on twisted pi-systems and EPR spectroscopic properties of the corresponding radical anions. In 1972 he joined the group of Professor J.F.M. Oth at the Swiss Federal Institute of Technology in Zürich where he worked in the field of dynamic NMR spectroscopy and electrochemistry. He received his habilitation from the ETH Zürich in 1977 and was appointed Privatdozent. In 1979 he became a Professor in the Department of Organic Chemistry, University of Cologne, and accepted an offer of a chair in Organic Chemistry at the University of Mainz in 1983. He received a call to the University of Göttingen in 1988.

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http://pubs.acs.org/doi/abs/10.1021/jacs.6b12630

https://cen.acs.org/articles/95/i49/molecules-of-the-year-2017.html?utm_source=Twitter&utm_medium=Social&utm_campaign=CEN&hootPostID=ea1deb5464b6231122901a3321f4ff5e

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This is a compilation for educational purposes only. P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

Highly active, separable and recyclable bipyridine iridium catalysts for C–H borylation reactions

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Nov 212017

Graphical abstract: Highly active, separable and recyclable bipyridine iridium catalysts for C–H borylation reactions

Highly active, separable and recyclable bipyridine iridium catalysts for C–H borylation reactions

Hind Mamlouk,^a Jakkrit Suriboot,^b Praveen Kumar Manyam,^a Ahmed AlYazidi,^a David E. Bergbreiter*^b and Sherzod T. Madrahimov*^a

*Corresponding authors

^aDepartment of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar
E-mail: sherzod.madrahimov@qatar.tamu.edu

^bDepartment of Chemistry, Texas A&M University, College Station, USA
E-mail: bergbreiter@tamu.edu

Abstract

Iridium complexes generated from Ir(I) precursors and PIB oligomer functionalized bpy ligands efficiently catalyzed the reactions of arenes with bis(pinacolato)diboron under mild conditions to produce a variety of arylboronate compounds. The activity of this PIB bound homogeneous catalyst is similar to that of an original non-recyclable catalyst which allows it to be used under milder conditions than other reported recyclable catalysts. This oligomer-supported Ir catalyst was successfully recovered through biphasic extraction and reused for eight cycles without a loss of activity. Biphasic separation after the initial use of the catalyst led to an insignificant amount of iridium leaching from the catalyst to the product, and no iridium leaching from the catalyst was observed in the subsequent recycling runs. Arylboronate products obtained after extraction are sufficiently pure as observed by ¹H and ¹³C-NMR spectroscopy that they do not require further purification.

Hind MAMLOUK, PhD

R&D in Organic Materials Chemistry Looking for a New Challenge

3-Chloro-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)anisole (5). Transparent oil. Yield: 87%.

1H NMR (600 MHz, CDCl3) δ 7.37 (s, 1H), 7.22 – 7.16 (m, 1H), 6.99 (s, 1H), 3.82 (s, 3H), 1.34 (s, 12H);

13C NMR (101 MHz, CDCl3) δ 159.88, 134.57, 126.84, 117.71, 117.43, 84.15, 55.52, 24.82.

GCMS: RT=14.55 min, M+ = 268.1 vs MW= 268.54 g.mol-1 .

Sherzod Madrahimov

Asst. Prof.

Texas A&M University at Qa… , Doha · Science

Research experience

Aug 2015–present

Asst. Prof.

Texas A&M University at Qatar · Chemistry

Qatar · Doha
Jul 2012–Jul 2015

PostDoc Position

Northwestern University · Department of Chemistry

United States · Evanston
Aug 2007–Jul 2012

Graduate student

University of Illinois, Urbana-Champaign · Department of Chemistry

United States · Urbana

Texas A&M University at Qatar

David Bergbreiter
Professor

Contact

Department of Chemistry
Texas A&M University
College Station, TX 77843-3255

P: 979-845-3437
F: 979-845-4719
bergbreiter@chem.tamu.edu

Current Activities

Our group explores new chemistry related to catalysis and polymer functionalization using the tools and precepts of synthetic organic chemistry to prepare functional oligomers or polymers that in turn are used to either effect catalysis in a greener, more environmentally benign way or to more efficiently functionalize polymers. Often this involves creatively combining the physiochemical properties of a polymer with the reactivity of a low molecular weight compound to form new materials with new functions. These green chemistry projects involve undamental research both in synthesis and catalysis but has practical aspects because of its relevance to practical problems.

A common theme in our catalysis studies is exploring how soluble polymers can facilitate homogeneous catalysis. Homogeneous catalysts are ubiquitously used to prepare polymers, chemical intermediates, basic chemicals and pharmaceuticals. Such catalysts often use expensive or precious metals or expensive ligands or are used at relatively high catalyst loadings. The products often contain traces of these catalysts or ligands – traces that are undesirable for esthetic reasons or because of the potential toxicity of these impurities. Both the cost of these catalysts of these issues require catalyst/product separation – separations that often are inefficient and lead to chemical waste. These processes also use volatile organic solvents – solvents that have to be recovered and separated. Projects underway in our lab explore how soluble polymers can address each of these problems. Examples of past schemes that achieve this goal in a general way as highlighted in the Figure below.

We also use functional polymers to modify existing polymers. Ongoing projects involve molecular design of additives that can more efficiently modify polymers’ physical properties. We also use functional polymers in covalent layer-by-layer assembly to surface polymers’ surface chemistry. An example of this work is our use of ‘smart’ polymers that reversibly change from being water soluble cold to being insoluble and hydrophobic on heating. Such polymers’ have been used by us to prepare ‘smart’ catalysts, ‘smart’ surfaces and membranes, and to probe fundamental chemistry underlying temperature and salt-dependent protein solvation.

Jakkrit Suriboot

Research Assistant at Texas A&M University

Image result for Praveen Kumar Manyam TEXAS

Dr. Praveen Kumar

Title: Research Assistant Professor

Education: M.S., I.I.T. Roorkee
Ph.D., Panjab University Chandigarh (2008)
Visiting Fellow (w/ Prof. G. G. Balint-Kurti), Bristol University, UK
Postdoctoral Research Associate (w/ Prof. Svetlana Malinovskaya), Stevens Institute of Technology, Hoboken, NJ
Senior Postdoctoral Research Associate (w/ Prof. Seogjoo Jang), Queens College of CUNY, NY

Office: Chemistry 010

Phone: 806-742-3124

Email: praveen.kumar@ttu.edu

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“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This is a compilation for educational purposes only. P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

amcrasto@gmail.com

Gram-Scale Synthesis of Amines Bearing a gem-Difluorocyclopropane Moiety

organic chemistry, spectroscopy, SYNTHESIS Comments Off

Nov 102017

Image result for National Taras Shevchenko University of Kyiv, Volodymyrska Street 64, Kyiv 01601, Ukraine

Ukraine

Abstract

The synthesis of monocyclic, spirocyclic and fused bicyclic secondary amines bearing a gem-difluorocyclopropane moiety via difluorocyclopropanation of unsaturated N-Boc derivatives using the trifluoromethyl(trimethyl)silane/sodium iodide [CF₃SiMe₃-NaI] system is described. The relative order of the substrate reactivity is established. It is shown that for the reactive alkenes the standard reaction conditions can be used, whereas for the substrates with low reactivity, slow addition of the Ruppert–Prakash reagent is necessary.

Gram-Scale Synthesis of Amines Bearing a gem-Difluorocyclopropane Moiety

Authors., Pavel S. Nosik,

DOI: 10.1002/adsc.201700857

Pavel S. Nosik,a.b Andrii O. Gerasov,a Rodion O. Boiko,a Eduard Rusanov,b Sergey V. Ryabukhin,c Oleksandr O. Grygorenko,c * Dmitriy M. Volochnyukb

a Spectrum Info Ltd., Life Chemicals Inc., Murmanska Street 5, Kyiv 02094, Ukraine

b Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Murmanska Street 5, Kyiv 02660, Ukraine

c National Taras Shevchenko University of Kyiv, Volodymyrska Street 64, Kyiv 01601, Ukraine

Image result for National Taras Shevchenko University of Kyiv, Volodymyrska Street 64, Kyiv 01601, Ukraine

* Corresponding author. E-mail: gregor@univ.kiev.ua.

Oleksandr Grygorenko

Ph D

Professor (Associate)

National Taras Shevchenko Univ… , Kiev · Faculty of Chemistry

National Taras Shevchenko University of Kyiv, Volodymyrska Street 64, Kyiv 01601, Ukraine

National Taras Shevchenko University of Kyiv

Department

Faculty of Chemistry

Image result for National Taras Shevchenko University of Kyiv, Volodymyrska Street 64, Kyiv 01601, Ukraine

Dmitriy M. Volochnyuk

Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Murmanska Street 5, Kyiv 02660, Ukraine

Dmitriy M. Volochnyuk was born in 1980 in Irpen, Kyiv region, Ukraine. He graduated from Kyiv State Taras Shevchenko University in 2002 and was awarded his M.S. degree in chemistry. He received his Ph.D. in organic chemistry in 2005 from the Institute of Organic Chemistry, National Academy of Sciences of Ukraine under the supervision of Dr. A. Kostyuk for research on the chemistry of enamines. At present, he divides his time between the Institute of Organic Chemisty, as Deputy Head of Organophosphorus Department and Senior Researcher, and Enamine Ltd (Kyiv, Ukraine), as Director of Chemistry. His main scientific interests are related to fluoroorganic, organophosphorus, heterocyclic and combinatorial chemistry, and multistep organic synthesis. He is a coauthor of more than 80 papers

Given that the incorporation of small fluorinated fragments in drug-like molecules continues to rise, this has created an onus on the synthetic community to provide robust, scalable routes to these molecules of interest. Grygorenko and co-workers have reported on a synthesis of amines featuring a gem-difluorocyclopropane moiety using the readily available Ruppert–Prakash reagent ( Adv. Synth. Catal. 2017, 10.1002/adsc.201700857).
Evaluating a series of olefins under the standard reaction conditions in refluxing THF indicated that only the most reactive olefins (gem-disubstituted) provided good yields of the desired cyclopropane, while other solvents proved to be ineffective. Conducting a control experiment omitting the substrate demonstrated that the key issue herein was competitive decomposition of the TMSCF₃ to a series of gaseous byproducts under the reaction conditions.
Whereas continuous flow provides a potential to mitigate against this, the current report demonstrated that slow addition of the reagent to the reaction mixture also provided a practical solution to this problem.
Employing this approach enabled not only excellent conversions and yields to be realized but also allowed reactivity trends to be identified. In general, gem-disubstituted are the most reactive with the trend correlating with steric hindrance.
For other classes of olefins, electronics are the major factor with the ability of the substituents to stabilize a positive charge in the transition state consistent with a nonsynchronous formation of the two sigma bonds in the cycloaddition the key consideration. The removal of the Boc-protecting group under standard acidic conditions provided the amines as their hydrochloride salts.
Eduard Rusanov

PhD

Head of Crystallographic Lab./Director of the crystallographic facility Nat. Acad. of Sci. Ukraine ‘Single Mjlecule Crystallography’ at IOC

Institute of Organic Chemistry… · DEPARTMENT OF PHYSICOCHEMICAL INVESTIGATIONS