Copper-catalyzed pyrrole synthesis from 3,6-dihydro-1,2-oxazines

organic chemistry, spectroscopy, SYNTHESIS Comments Off

Jul 262018

Copper-catalyzed pyrrole synthesis from 3,6-dihydro-1,2-oxazines

Naoki Yasukawa,^a Marina Kuwata,^a Takuya Imai,^a Yasunari Monguchi,^a Hironao Sajiki*^a and Yoshinari Sawama*^a

Author affiliations

*Corresponding authors

^aLaboratory of Organic Chemistry, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
E-mail: sajiki@gifu-pu.ac.jp, sawama@gifu-pu.ac.jp
Fax: +81-58-230-8109

Abstract

Highly-functionalized pyrroles could be effectively synthesized from 3,6-dihydro-1,2-oxazines using a heterogeneous copper on carbon (Cu/C) under neat heating conditions. Furthermore, the in situ formation of 3,6-dihydro-1,2-oxazines via the hetero Diels–Alder reaction between nitroso dienophiles and 1,3-dienes and the following Cu/C-catalyzed pyrrole synthesis also provided the corresponding pyrrole derivatives in a one-pot manner.

Brown solid; M. p. 107–108 o C;

IR (ATR) cm-1 : 3064, 2923, 2851, 1687, 1596, 1562, 1541, 1498, 1488, 1459, 1451, 1422, 1390, 1343, 1319, 1256, 1187, 1098, 1073, 1053, 1037, 1009;

1 H NMR (500 MHz, CDCl3): δ 7.37–7.28 (m, 5H), 7.17 (d, J = 8.0 Hz, 2H), 6.99 (d, J = 8.0 Hz, 2H), 6.95 (dd, J = 2.0, 3.0 Hz, 1H), 6.45 (dd, J = 2.0, 3.0 Hz, 1H), 6.37 (dd, J = 3.0, 3.0 Hz, 1H);

13C NMR (125 MHz, CDCl3): δ 140.19, 132.52, 131.85, 131.19, 129.65, 129.14, 126.84, 125.69, 124.83, 120.24, 110.97, 109.38;

ESI-HRMS m/z: 298.0231([M+H+ ]); Calcd for C16H13NBr: 298.0226.

//////////3,6-dihydro-1,2-oxazines

A borrowing hydrogen methodology: palladium-catalyzed dehydrative N-benzylation of 2-aminopyridines in water

organic chemistry, spectroscopy, SYNTHESIS Comments Off

Jul 042018

Graphical abstract: A borrowing hydrogen methodology: palladium-catalyzed dehydrative N-benzylation of 2-aminopyridines in water

A borrowing hydrogen methodology: palladium-catalyzed dehydrative N-benzylation of 2-aminopyridines in water

Hidemasa Hikawa,*^a Hirokazu Imamura,^a Shoko Kikkawa^a and Isao Azumaya*^a

Author affiliations

*Corresponding authors

^aFaculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Japan
E-mail: hidemasa.hikawa@phar.toho-u.ac.jp, isao.azumaya@phar.toho-u.ac.jp

Image result for Hidemasa Hikawa Toho University

Isao Azumaya

Abstract

We demonstrate a greener borrowing hydrogen methodology using the π-benzylpalladium system, which offers an efficient and environmentally friendly dehydrative N-monobenzylation of 2-aminopyridines with benzylic alcohols in the absence of base. The crossover experiment using benzyl-α,α-d₂ alcohol and 3-methylbenzyl alcohol afforded H/D scrambled products, suggesting that the dehydrative N-benzylation in our catalytic system involves a borrowing hydrogen pathway. KIE experiments show that C–H bond cleavage at the benzylic position of benzyl alcohol is involved in the rate-determining step (KIE = 2.9). This simple base-free protocol can be achieved under mild conditions in an atom-economic process, affording the desired products in moderate to excellent yields.

N-Benzylpyridin-2-amine 3a 1 Yield 165 mg (90%) as a white solid; mp 90-91 C; IR (KBr) (cm-1) 3226, 3029, 1600, 1575; 1H NMR (400 MHz, CDCl3):  4.50 (d, J=5.7 Hz, 2H), 4.95 (brs, 1H), 6.36 (dt, J=8.5, 0.9 Hz, 1H), 6.58 (ddd, J=7.1, 5.0, 0.9 Hz, 1H), 7.23-7.36 (m, 4H), 7.39 (dd, J=8.7, 7.1, 1.8 Hz, 1H), 8.09 (ddd, J=5.0, 1.8, 0.9 Hz, 2H); 13C-NMR (100 MHz, CDCl3): 46.3, 106.8, 113.1, 127.2, 127.4, 128.6, 137.5, 139.2, 148.2, 158.6; MS (FAB): m/z 185 [M+H]+ .

/////////////borrowing hydrogen methodology, palladium-catalyzed, dehydrative N-benzylation, 2-aminopyridines,

SNS-Ligands for Ru-Catalyzed Homogeneous Hydrogenation and Dehydrogenation Reactions

organic chemistry, spectroscopy Comments Off

Jul 042018

A detailed study of literature-known and novel S-containing pincer-type ligands for ruthenium-catalyzed homogeneous hydrogenation and dehydrogenation reactions was carried out. The scope and limitations of these catalysts were carefully investigated, and it was shown that simple bench-stable SNS–Ru complexes can be used to facilitate the hydrogenation of a variety of different substrates at a maximum H₂ pressure of 20 bar under operationally simple, easy to scale up, glovebox-free conditions by using starting materials and reagents that do not require any special purification prior to use. It was also shown that such complexes can be used to catalyze the dehydrogenative coupling of alcohols and amines to get amides as well as for the dehydrogenative dimerization of alcohols to esters.

SNS-Ligands for Ru-Catalyzed Homogeneous Hydrogenation and Dehydrogenation Reactions

Johannes Schörgenhumer^†, Axel Zimmermann*^‡, and Mario Waser*^†

^†Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria

^‡Patheon Austria, part of Thermo Fisher Scientific, St. Peterstr. 25, 4020 Linz, Austria

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.8b00142

*E-mail: mario.waser@jku.at. Tel: +4373224685411. Fax: +437322468545402., *E-mail: axel.zimmermann@patheon.com.

https://pubs.acs.org/doi/10.1021/acs.oprd.8b00142

Complex IIb:

Method A was applied, using 180 mg of ligand 11b (1.09 mmol) and 993 mg of 27 (1.04 mmol) to give the complex IIb as yellow powder in 83% yield. The complex was isolated as mixture of three isomers.

1 H-NMR (CDCl3, 300 MHz, 298 K), δ / ppm: 7.75-7.50 (m, 10H), 7.41-7.25 (m, 16H), 5.05 (bs, 1H), 3.73-2.9 (m, 9H), 2.71-2.41 (m, 3H), 1.89-1.71 (m, 1H), 1.64-1.54 (m, 12H);

31P-NMR (CDCl3, 121 MHz, 298 K), δ / ppm: 50.6 (59%), 49.0 (24%), 47.6 (17%);

13C NMR (75 MHz, CDCl3, 298 K): δ / ppm = 137.1 (d, J = 39.5 Hz), 134.6 (d, J = 10.0 Hz), 129.3, 127.8 (d, J = 8.9 Hz), 49.0, 42.2, 17.7;

HRMS (ESI+): m/z calcd for C24H30ClNPRuS2 [M – Cl]+: 564.0284; found: 564.0272.

1 H-NMR (CDCl3, 300 MHz, 298 K), δ / ppm: 7.75-7.50 (m, 10H), 7.41-7.25 (m, 16H), 5.05 (bs, 1H), 3.73-2.9 (m, 9H), 2.71-2.41 (m, 3H), 1.89-1.71 (m, 1H), 1.64-1.54 (m, 12H);

31P-NMR (CDCl3, 121 MHz, 298 K), δ / ppm: 50.6 (59%), 49.0 (24%), 47.6 (17%);

13C NMR (75 MHz, CDCl3, 298 K): δ / ppm = 137.1 (d, J = 39.5 Hz), 134.6 (d, J = 10.0 Hz), 129.3, 127.8 (d, J = 8.9 Hz), 49.0, 42.2, 17.7;

///////////////SNS-Ligands, Ru-Catalyzed, Homogeneous Hydrogenation, Dehydrogenation Reactions

Absolute Quantification of Lipophilic Shellfish Toxins by Quantitative Nuclear Magnetic Resonance Using Removable Internal Reference Substance with SI Traceability

organic chemistry Comments Off

Jun 282018

Absolute Quantification of Lipophilic Shellfish Toxins by Quantitative Nuclear Magnetic Resonance Using Removable Internal Reference Substance with SI Traceability

Tsuyoshi KATO, Maki SAITO, Mika NAGAE, Kazuhiro FUJITA, Masatoshi WATAI, Tomoji IGARASHI, Takeshi YASUMOTO, and Minoru INAGAKI

Keywords: Lipophilic shellfish toxin, okadaic acid, dinophysistoxin-1, polyethers, qNMR, AQARI

Analytical Sciences, 2016, 32(7), 729.

DOI: 10.2116/analsci.32.729

Read abstract
View this article in J-STAGE
Okadaic acid (OA), a lipophilic shellfish toxin, was accurately quantified using quantitative nuclear magnetic resonance with internal standards for the development of an authentic reference standard. Pyridine and the residual proton in methanol-d₄ were used as removable internal standards to limit any contamination. They were calibrated based on a maleic acid certified reference material. Thus, the concentration of OA was traceable to the SI units through accurate quantitative NMR with an internal reference substance. Signals from the protons on the oxygenated and unsaturated carbons of OA were used for quantification. A reasonable accuracy was obtained by integrating between the lower and upper ¹³C satellite signal range when more than 4 mg of OA was used. The best-determined purity was 97.4% (0.16% RSD) when 20 mg of OA was used. Dinophysistoxin-1, a methylated analog of OA having an almost identical spectrum, was also quantified by using the same methodology.

////////////

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.

//////////////

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.

///////////

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.

//////////

Catalytic C-H amination at its limits: challenges and solutions

organic chemistry, Uncategorized Comments Off

Nov 232017

Catalytic C-H amination at its limits: challenges and solutions

Org. Chem. Front., 2017, 4,2500-2521
DOI: 10.1039/C7QO00547D, Review Article

Damien Hazelard, Pierre-Antoine Nocquet, Philippe Compain
Pushing C-H amination to its limits fosters innovative synthetic solutions and offers a deeper understanding of the reaction mechanism and scope.

Catalytic C–H amination at its limits: challenges and solutions

Damien Hazelard,^a Pierre-Antoine Nocquet^a and Philippe Compain*^a

*Corresponding authors

^aLaboratoire de Synthèse Organique et Molécules Bioactives (SYBIO), Université de Strasbourg/CNRS (UMR 7509), Ecole Européenne de Chimie, Polymères et Matériaux (ECPM), 25 rue Becquerel, 67087 Strasbourg Cedex 2, France
E-mail: philippe.compain@unistra.fr

Abstract

Catalytic C–H amination reactions enable direct functionalization of non-activated C(sp³)–H bonds with high levels of regio-, chemo- and stereoselectivity. As a powerful tool to unlock the potential of inert C–H bonds, C–H amination chemistry has been applied to the preparation of synthetically challenging targets since major simplification of synthetic sequences are expected from this approach. Pushing C–H amination to its limits has led to a deeper understanding of the reaction mechanism and scope. In this review, we present a description of the specific challenges facing catalytic C–H amination in the synthesis of natural products and related compounds, as well as innovative tactics created to overcome them. By identifying and discussing the major insights gained and strategies designed, we hope that this review will stimulate further progress in C–H amination chemistry and beyond.

Conclusion Since the seminal works of Du Bois in the early 2000s, the pace of discovery in the field of metal-catalysed C–H amination has been breath-taking. Not surprisingly, this synthetic tool has been applied to the total synthesis of many compounds of interest, given the high prevalence of the amino group in natural products and synthetic pharmaceuticals.67 Chemist’s confidence in the high potential of the C–H amination methodology to unlock inert C–H bonds has been demonstrated by its application to more and more challenging substrates. This has been a powerful drive for progress in the field. New valuable insights have been gained allowing, for example, a better regiochemical control via stereoelectronic and/or conformational effects. Innovative strategies have been discovered to direct the insertion event in substrates bearing a large degree of attendant functionality. Solutions have spanned from the elegant exploitation of kinetic isotope effects to the tactical use of protecting groups with different sizes or electronic characteristics. Systematic exploration of different catalytic systems has been also performed leading to the opening of new possibilities in C–H amination technology. Manganese-based catalysts have thus given rise to nitrenoids that overcome the low reactivity of primary aliphatic C–H bonds without interfering with weaker secondary/tertiary C–H bonds. Despite these impressive achievements, much remains to be done. Counterintuitive selectivity and unexplained reactivity should serve as a reminder that further studies are highly needed to understand in depth catalytic C–H amination chemistry. Many challenges remain on the way, from basic to applied research. A clear mechanistic view based on definitive evidence concerning the details of the C–N bond forming process would undoubtedly facilitate the rational design of efficient catalytic systems leading to higher regio-, chemio- and stereoselectivity. In particular, the quest for site-selective C–H amination through catalyst control has to be pursued.10d,e In this context, the development of efficient intermolecular C–H amination process still represents a major challenge and upcoming advancements are expected to increase the impact of this technology in organic synthesis. Future progress made in the field of catalytic C–H amination chemistry might also lead to industrial-scale applications in the next decade. It is likely that total synthesis of synthetically challenging targets related to natural products will continue to be a powerful driving force towards this goal.

/////////////

“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