56762-93-7Relevant academic research and scientific papers
An improved protocol for the preparation of (S)-vinylglycine from (S)-methionine
Kuechenthal,Migenda, Julia,Polednia, Magdalena,Maison, Wolfgang
, p. 443 - 448 (2010)
We present an optimized procedure for the synthesis of (S)-vinylglycine from (S)-methionine. The key step is a solvent free pyrolysis of an intermediate sulfoxide at high temperature. Using our optimized reaction conditions, Cbz-protected vinylglycine was
Electrophilic Chlorine from Chlorosulfonium Salts: A Highly Chemoselective Reduction of Sulfoxides
Acosta-Guzmán, Paola,Mahecha-Mahecha, Camilo,Gamba-Sánchez, Diego
supporting information, p. 10348 - 10354 (2020/07/13)
Herein, we describe a selective late-stage deoxygenation of sulfoxides based on a novel application of chlorosulfonium salts and demonstrate a new process using these species generated in situ from sulfoxides as the source of electrophilic chlorine. The use of highly nucleophilic 1,3,5-trimethoxybenzene (TMB) as the reducing agent is described for the first time and applied in the deoxygenation of simple and functionalized sulfoxides. The method is easy to handle, economic, suitable for gram-scale operations, and readily applied for poly-functionalized molecules, as demonstrated with more than 45 examples, including commercial medicines and analogues. We also report the results of competition experiments that define the more reactive sulfoxide and we present a mechanistic proposal based on substrate and product observations.
An efficient, stereocontrolled and versatile synthetic route to bicyclic partially saturated privileged scaffolds
Bond, Andrew D.,Hanby, Abigail R.,King, Thomas A.,Moss, Thomas A.,Sore, Hannah F.,Spring, David R.,Stewart, Hannah L.
supporting information, p. 6818 - 6821 (2020/07/04)
Herein, we describe the development of a simple, high yielding and stereocontrolled strategy for the synthesis of a series of triazolopiperazines and other biologically relevant fused scaffolds from optically active amino acids. This route was applied to the synthesis of 22 scaffolds containing new, previously inaccessible vectors and used to access a novel analogue of ganaplacide.
C(sp3)?H Cyanation Promoted by Visible-Light Photoredox/Phosphate Hybrid Catalysis
Wakaki, Takayuki,Sakai, Kentaro,Enomoto, Takafumi,Kondo, Mio,Masaoka, Shigeyuki,Oisaki, Kounosuke,Kanai, Motomu
supporting information, p. 8051 - 8055 (2018/06/15)
Inspired by the reaction mechanism of photo-induced DNA cleavage in nature, a C(sp3)?H cyanation reaction promoted by visible-light photoredox/phosphate hybrid catalysis was developed. Phosphate radicals, generated by one-electron photooxidation of phosphate salt, functioned as a hydrogen-atom-transfer catalyst to produce nucleophilic carbon radicals from C(sp3)?H bonds with a high bond-dissociation energy. The resulting carbon radicals were trapped by a cyano radical source (TsCN) to produce the C?H cyanation products. Due to the high functional-group tolerance and versatility of the cyano group, the reaction will be useful for realizing streamlined building block syntheses and late-stage functionalization of drug-like molecules.
Amidation of unactivated ester derivatives mediated by trifluoroethanol
McPherson, Christopher G.,Caldwell, Nicola,Jamieson, Craig,Simpson, Iain,Watson, Allan J. B.
supporting information, p. 3507 - 3518 (2017/04/26)
A catalytic amidation protocol mediated by 2,2,2-trifluoroethanol has been developed, facilitating the condensation of unactivated esters and amines, furnishing both secondary and tertiary amides. The complete scope and limitations of the method are described, along with modified conditions for challenging substrates such as acyclic secondary amines and chiral esters with retention of chiral integrity.
Carica papaya lipase catalysed resolution of β-amino esters for the highly enantioselective synthesis of (S)-dapoxetine
You, Pengyong,Qiu, Jian,Su, Erzheng,Wei, Dongzhi
, p. 557 - 565 (2013/03/13)
An efficient synthesis of the (S)-3-amino-3-phenylpropanoic acid enantiomer has been achieved by Carica papaya lipase (CPL) catalysed enantioselective alcoholysis of the corresponding racemic N-protected 2,2,2-trifluoroethyl esters in an organic solvent. A high enantioselectivity (E > 200) was achieved by two strategies that involved engineering of the substrates and optimization of the reaction conditions. Based on the resolution of a series of amino acids, it was found that the structure of the substrate has a profound effect on the CPL-catalysed resolution. The enantioselectivity and reaction rate were significantly enhanced by switching the conventional methyl ester to an activated trifluoroethyl ester. When considering steric effects, the substituted phenyl and amino groups should not both be large for the CPL-catalysed resolution. The mechanism of the CPL-catalysed enantioselective alcoholoysis of the amino acids is discussed to delineate the substrate requirements for CPL-catalysed resolution. Finally, the reaction was scaled up, and the products were separated and obtained in good yields (≥ 80 %). The (S)-3-amino-3- phenylpropanoic acid obtained was used as a key chiral intermediate in the synthesis of (S)-dapoxetine with very high enantiomeric excess (> 99 %). A carica papaya lipase catalysed resolution of N-protected β-phenylalanine esters has been developed. High enantioselectivity was achieved by two strategies that involved engineering of the substrates and optimization of the reaction conditions. After 50 % conversion, the products were separated and used as key chiral intermediates for the synthesis of (S)-dapoxetine with > 99 % ee. Copyright
Macrocyclic Cysteine Protease Inhibitors and Compositions Thereof
-
, (2011/02/18)
The present invention provides a novel class of macrocyclic compounds, which are useful as cysteine protease inhibitors. Also provided are novel intermediates and methods of preparing the compounds. The invention also provides pharmaceutical compositions
An efficient and scalable synthesis of N-(benzyloxycarbonyl)- and N-(methyloxycarbonyl)-(S)-vinylglycinol
Lumbroso, Alexandre,Coeffard, Vincent,Le Grognec, Erwan,Beaudet, Isabelle,Quintard, Jean-Paul
supporting information; experimental part, p. 3226 - 3228 (2010/08/19)
An efficient and scalable synthesis of N-(benzyloxycarbonyl)- and N-(methyloxycarbonyl)-(S)-vinylglycinol has been reported starting from the commercially available (l)-methionine. The scale-up preparation consisted of 5 steps and delivered up to 50 g of the desired N-protected β-amino alcohols in 32% and 36% overall yields.
Straightforward synthesis of chiral silylated amino acids through hydrosilylation
Marchand, Damien,Martinez, Jean,Cavelier, Florine
experimental part, p. 3107 - 3112 (2009/05/11)
A method using hydrosilylation of unsaturated amino acids was developed and optimised to obtain silylated amino acids. The platinum (Bu4N) 2PtCl6 complex was identified as the best catalyst, and the procedure tolerated dif
Resolution of non-protein amino acids via Carica papaya lipase-catalyzed enantioselective transesterification
Miyazawa, Toshifumi,Onishi, Kazuki,Murashima, Takashi,Yamada, Takashi,Tsai, Shau-Wei
, p. 2569 - 2573 (2007/10/03)
Carica papaya lipase-catalyzed transesterification of the 2,2,2-trifluoroethyl esters of N-benzyloxycarbonylated dl-amino acids carrying aliphatic side chains proceeded smoothly and, in almost all the cases, enantiospecifically (E = >200), affording the l-methyl esters and leaving the d-trifluoroethyl esters intact.
