The improved process for the synthesis of (±)-tapentadol, the FDA-approved analgesic drug, is achieved from tetrahydrothiopyran-4-one as the five-carbon source.
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A general method for the aldol condensation of aromatic ketones with aldehydes was developed under continuous-flow conditions using a commercially available, strongly basic anion-exchange resin (A26) as catalyst. This procedure, in addition to exhibiting a wide substrate scope, promoted carbon–carbon bond formation under mild conditions using a quasi-stoichiometric ratio of starting reagents with good to excellent yields, thereby forming a limited amount of waste and allowing the process to be applied to sequential-flow systems. A proof of concept was developed in the first fully heterogeneously catalyzed two-step flow synthesis of donepezil, which is a blockbuster commercial anti-Alzheimer’s drug.
https://pubs.acs.org/doi/10.1021/acs.oprd.9b00048
////////donepezil
Conventional enantioselective preparative chromatographic separation using columns packed with chiral stationary phase is characterized by a 50% yield constraint. Racemization of the undesired enantiomer and recycling the formed mixture is an attractive option to tackle this limit. To implement this concept, potential is seen in particular in applying enzymes immobilized in a second fixed bed. However, the identification of suitable operating conditions and the direct connection of a chromatographic column and an enzymatic reactor is not trivial. The paper presents results of an experimental study applying jointly a batch-wise operated chiral Chirobiotic T column to resolve the two enantiomers of mandelic acid (MA) and a mandelate racemase immobilized on Eupergit CM. The general concept could be successfully demonstrated over several cycles focusing on the provision of (S)-MA. A mathematical model was developed in order to illustrate essential process features and to quantitatively describe the coupled separation and racemization processes. The key ingredients of this model, namely, the adsorption isotherms of the two enantiomers on the chiral column and the rate of racemization in the enzymatic reactor, were determined experimentally. The potential of applying the model for further process optimization and generalization is indicated.
Combination of Enantioselective Preparative Chromatography and Racemization: Experimental Demonstration and Model-Based Process Optimization
link https://pubs.acs.org/doi/10.1021/acs.oprd.8b00254
Dr. Katarzyna Wrzosek
Max-Planck Institute for Dynamics of Complex Technical System, Physical and Chemical Foundations of Process Engineering, 39106 Magdeburg, Germany
*E-mail: wrzosek@mpi-magdeburg.mpg.de.
M. Sc. Isabel Harriehausen
Prof. Dr.-Ing. Andreas Seidel-Morgenstern
Magdeburg, Germany
Grüne Zitadelle Von Magdeburg
Magdeburg Cathedral
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///////////////enantioselective chromatography, enzymatic reactor, equilibrium dispersion model, mandelate racemase, racemization
Here we describe an efficient and cost-effective chemoenzymatic synthesis of the β-lactamase inhibitor avibactam starting from commercially available ethyl 5-hydroxypicolinate hydrochloride. Avibactam was synthesized in 10 steps with an overall yield of 23.9%. The synthetic route features a novel lipase-catalyzed resolution step during the preparation of (2S,5S)-ethyl 5-hydroxypiperidine-2-carboxylate, a valuable precursor of the key intermediate ethyl (2S,5R)-5-((benzyloxy)amino)piperidine-2-carboxylate. Our synthetic route was used to produce 400 g of avibactam sodium salt.
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Synthesis with Catalysts Pvt Ltd was founded with an aim to help aromatic chemical, essential oil, pharmaceutical, API manufacturers to develop new products, increase productivity and improve production methodologies.
We have an advanced research and development centre where we innovate new chemical processes and improve the existing ones and help our customers implement the same. We support our research with pilot production of the products.
We are also developing precious metal complexes, Catalysts, Legends etc.
We are continuously working to reset standards of purity with our products.
The team at Synthesis with Catalysts Pvt Ltd has an vast experience and well renowned scientists of India have found it suitable to continue their Research in our facilities. The team with Synthesis with Catalysts Pvt Ltd has presented countless number of research papers all across the world.
We have a world class lab with all advance analytical testing machines.
Synthesis with Catalysts Pvt Ltd.’s strength lies in its state-of- the-art infrastructure and R&D capabilities. Innovative process development is the foundation of SWC’s success. Our team of highly qualified R&D experts in process of research and technology development work 24 hours for inventing new processes and Optimizing product development capabilities. Our main focus is developing innovative processes, which could help our partners in reducing their costs and production time. Our Scientists constantly work for cost-effective ways of developing products, ensuring better service for our clients.
////////////1,2 Diaminocyclohexane, Synthesis with Catalysts Pvt Ltd
This review highlights the progress of aqueous fluoroalkylation over the past few decades. Fluorine-containing functionalities are important design elements in new pharmaceuticals, agrochemicals, and functional materials, due to their unique effects on the physical, chemical, and/or biological properties of a molecule. Because the environmental concerns are receiving increasing attention in organic synthesis, the development of methods for the mild, environment-friendly, and efficient incorporation of fluorinated or fluoroalkylated groups into the target molecules is of broad interest. At the early stage, most of the fluoroalkylation reactions and their variants were thought in principle to be hydrophobic. Recently, the environment-benign fluoroalkylation reactions by taming nucleophilic, radical, or electrophilic fluoroalkylation reagents in water or in the presence of water have been explored, building a new prospect for green chemistry. The use of significant catalytic systems and/or the newly developed reagents is the key to the success of these reactions. Water is used as a (co)solvent and/or a reactant in aqueous fluoroalkylation, including trifluoromethylation, difluoromethylation, monofluoromethylation, trifluoroethylation, perfluoroalkylation, trifluoromethylthiolation, and other conversions, under environment-friendly conditions. Although great accomplishments have been achieved, they are just the tip of the iceberg with a wide scope for improvement. This review will draw great attention and inspire more contributions in the development of new aqueous fluoroalkylation reactions
Conclusion
In conclusion, aqueous fluoroalkylation including trifluoromethylation, difluoromethylation, monofluoromethylation, trifluoroethylation, perfluoroalkylation, trifluoromethylthiolation, and difluoromethylthiolation are summarized in this review.
The successful assembly of nucleophilic, radical, and/or electrophilic fluoroalkylation reagents and water in fluoroalkylation reactions opens a new prospect for green chemistry. The valid catalytic systems and the newly developed reagents contribute greatly for the success of the aqueous fluoroalkylation. As a provisional conclusion, the shelf-stable electrophic and radical fluoroalkylation reagents such as “+CF3”, “+CF2H”, “ +CH2CF3”, RfnSO2M (M = Na, 1/2Zn, Cl), RfnX (X = I, Br), and “+ SCF3” reagents are basically compatible with water or aqueous media, which enable a variety of aqueous fluoroalkylation reactions under mild conditions. In the case of nucleophilic fluoroalkylation reagents that are moisture-sensitive (e.g., “−CF3” and “− SCF3” sources), the choice of an appreciate transition-metal partner to stabilize the fluorinated anions is crucial to promote the reaction.
By coupling with the right transition metals, these sensitive fluoroalkylation reagents or intermediates would have sufficient lifetimes to finish the target conversions. Water is abundant and environmentally benign, and it has advantages such as high dielectric constant, large cohesive energy density, and strong hydrogen bonding interaction, which desirably influence the efficiency and selectivity of chemical reactions. In this reviw, water works as a (co)solvent and/or a reactant to facilitate the fluoroalkylation by increasing the dissolving of the reaction participants, providing a proton donor, or behaving as a O-nucleophile.
The fluoroalkylation reactions performed in aqueous media are mild, easily controlled, and environmental friendly, which fit well the principles of green chemistry. Although breakthroughs have been made, siginificant improvement is still neccessary for a wide range of fluoroalkylation reactions. A tough question is whether the direct trifluoromethoxylation can be performed in aqueous conditions, despite the reaction of excess AgOCF3 with α-diazo esters surviving in CH3CN in the presence of residue moisture or a trace amount of D2O (Scheme 120).155 The ionic [Me4N][SCF3] and [Me4N][SeCF3] salts, and their variants containing free − SCF3 or − SeCF3 anions, also encounter similar problems, even through trace of water proved to be essential for the functionalization of α-diazo carbonyls.156,157 The sensitive −XCF3 (X = O, S, Se) anions tend to undergo α-fluorine elimination to generate fluoride ( − F) and carbonic difluoride (CXF2), and the presence of water is generally believed to accelerate this transformation, leading to rapid decomposition of these reagents.
We hope that this review will attract more interests and contributions in the development of aqueous fluoroalkylation with these extraordinary reagents. Aqueous fluoroalkylation methods have changed the way to synthesize fluorinated molecules in terms of the biological and physicochemical properties. Since the aspects of green chemistry have drawn much attention from society, the pursuit of more efficient and milder reaction conditions for greener fluoroalkylation in aqueous media will never be terminated. We hope that this review will serve as a guide to understand and as an appeal to engage in the field of green fluorine chemistry.
To meet the principles of green chemistry, the development of new fluoroalkylation reagents and efficient catalytic systems will be continuously vital for the mild and environment-benign fluoroalkylation. It is anticipated that a growing number of green fluoroalkylation methodologies in aqueous media will arise in the near future.
* Corresponding authors
Professor of Enzymology and Biophysical Chemistry
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
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.
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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Artemisinin is a kind of natural antimalarial drug exhibiting low toxicity with a very fast action against malaria. Solvent extraction is the most widely used method to separate artemisinin from the Chinese medicinal herb Artemisia annua L. In this study, a series of monoether based solvents have been proposed to extract artemisinin and propylene glycol methyl ether (PGME) was found to be the most appropriate one for this extraction. Ultrasonic irradiation was demonstrated to be able to assist artemisinin extraction. Influences of extraction conditions, including liquid/solid ratio, extraction temperature, ultrasonic time, ultrasonic power, on the extraction efficiency were discussed by single factor experiments, and the main influence factors were optimized by responds surface method. The extraction mechanism was explored with spectroscopic characterizations, and kinetics of this process was also studied. Results indicate that ultrasonic assisted extraction using PGME has faster extraction rate than conventional solvents, and ultrasonic can significantly enhance mass transfer. Compared with conventional extraction, the process developed here exhibited higher efficiency (13.79 mg/g vs. 13.29 mg/g) and short extraction time (decreased from 8 h to 0.5 h) at a relatively low temperature. In addition, PGME has low toxicity and volatility, making the extraction process more safe and reliable. Therefore, this proposed method demonstrates that PGME based ultrasonic assisted extraction is a rapid, efficient, simple and safe technique for natural product extraction.
/////////// Artemisinin, Artemisia Annua L, extraction
Assistant Professor
rabnawaz@msu.edu
Telephone: 517-432-4870
Rabnawaz’s Research Group
School of Packaging
Dr. Cheng earned his PhD from South Dakota State University in May 2017. He has extensive research experiences in biomass pyrolysis and liquefaction, bio-oil catalytic cracking and hydrodeoxygenation, catalyst design, preparation, characterization and evaluation, food extruding, nano cellulose and protein peptides production, polymer synthesis, characterization and application.
Project Titles worked on: Innovation for Improved Sustainability: Scalable Approach for the Preparation of Thermoplastic Starches and their Composites for Applications in Biodegradable Packaging .
Duration in the group: August 2017- Present
Areas of Interest: Polycarbonates and polyesters synthesis, characterization and application.
MSU email Id: chengsho@msu.edu
 |
Ian Wyman
Education: Ph.D., Queen’s University, Kingston, Ontario Email: wymani@chem.queensu.ca |
Approximately 99% of the plastics produced today are petroleum-based, and the packaging industry alone consumes over 38% of these plastics. In this review, we argue that renewable polyesters can provide a key milestone as renewable plastics in the route toward green packaging. This review describes different classes of polyesters with particular regard to their potential use as packaging materials. Some of the families of polyesters discussed include poly(ethylene terephthalate) and its renewable analogs, poly(lactic acid), poly(hydroxyalkanoates), and poly(epoxy anhydrides). The synthesis of polyesters is discussed from a green chemistry perspective. A structure–property correlation among the various polyesters is also discussed. The challenges that currently hinder the widespread adoption of polyesters as leading packaging materials are reviewed. The environmental footprint and end of life scenario of polyesters are discussed. Finally, future research directions are summarized as a possible roadmap towards the widespread adoption of renewable polyesters as sustainable packaging materials.
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Assistant Professor
rabnawaz@msu.edu
Telephone: 517-432-4870
Rabnawaz’s Research Group
School of Packaging
I have published more than 20 research articles in the field of polymer and materials sciences. Our initial endeavors can be divided into three broad categories:
Our projects are highly applied, and we expect close collaboration with world-leading industries. These partnerships will offer unique training and career opportunities for the group members.
info@synthesiswithcatalysts.com
