7782-25-4Relevant academic research and scientific papers
Introduction of single mutation changes arylmalonate decarboxylase to racemase
Terao, Yosuke,Miyamoto, Kenji,Ohta, Hiromichi
, p. 3600 - 3602 (2006)
The introduction of only one mutation based on the estimated reaction mechanism endowed arylmalonate decarboxylase with a racemase activity, which catalyses racemisation of α-arylpropionates. The Royal Society of Chemistry 2006.
Entrapment of a chiral cobalt complex within silver: A novel heterogeneous catalyst for asymmetric carboxylation of benzyl bromides with CO2
Yang, Heng-Pan,Yue, Ying-Na,Sun, Qi-Long,Feng, Qiu,Wang, Huan,Lu, Jia-Xing
supporting information, p. 12216 - 12219 (2015/07/27)
A novel way to accommodate heterogeneous catalysis, CO2 fixation and asymmetric synthesis on one catalyst is reported. The [Co]@Ag composite was prepared for the first time and used for asymmetric carboxylation of benzyl bromides with CO2. All the procedures were performed under mild conditions. Moreover, the [Co]@Ag composite has terrific stability and reusability.
Enantiospecific, regioselective cross-coupling reactions of secondary allylic boronic esters
Chausset-Boissarie, Laetitia,Ghozati, Kazem,Labine, Emily,Chen, Jack L.-Y.,Aggarwal, Varinder K.,Crudden, Cathleen M.
, p. 17698 - 17701 (2014/01/17)
An original syn: The first enantioselective Suzuki-Miyaura cross-coupling of chiral, enantioenriched secondary allylic boronic esters is described (see scheme; DME=dimethoxyethane, Bpin = pinacolboryl, dba = dibenzylideneacetone). Mechanistic studies show that the reactions proceed via γ-selective transmetalation followed by reductive elimination. The reaction provides the first independent confirmation that the transmetalation of boronic esters proceeds via a syn pathway. Copyright
Directed evolution of an enantioselective lipase with broad substrate scope for hydrolysis of α-substituted esters
Engstroem, Karin,Nyhlen, Jonas,Sandstroem, Anders G.,Baeckvall, Jan-E.
supporting information; experimental part, p. 7038 - 7042 (2010/07/05)
A variant of Candida antarctica lipase A (CalA) was developed for the hydrolysis of α-substituted p-nitrophenyl esters by directed evolution. The E values of this variant for 7 different esters was 45-276, which is a large improvement compared to 2-20 for the wild type. The broad substrate scope of this enzyme variant is of synthetic use, and hydrolysis of the tested substrates proceeded with an enantiomeric excess between 95-99%. A 30-fold increase in activity was also observed for most substrates. The developed enzyme variant shows (R)-selectivity, which is reversed compared to the wild type that is (S)-selective for most substrates.
Enantiopure tert-butyl(phenyl)phosphine oxide. Chirality-recognition ability and mechanism
Ribeiro, Nigel,Saigo, Kazuhiko
experimental part, p. 2704 - 2708 (2010/04/29)
When enantiopure tert-butyl(phenyl)phosphine oxide 1 was used as a resolving agent, it showed an acceptable to good chirality-recognition ability for several kinds of racemic carboxylic acids 2. A study on a chirality-recognition mechanism based on X-ray crystallographic analyses of the diastereomeric complexes of 2 with 1 revealed that the complex crystals consisted of helical columns and that 1 was not responsible for the formation of the helical column and occupied a void between the columns; although 1 interacted with 2 via a hydrogen bond to primarily form a pair with 2, the complex crystals were mainly stabilized by the accumulation of weak interactions, such as CH/π, π/π and CH...O interactions, between 1/1, 1/2 and 2/2.
Enantioselective hydrolysis of various racemic α-substituted arylacetonitriles using Rhodococcus sp. CGMCC 0497
Wu, Zhong-Liu,Li, Zu-Yi
, p. 3305 - 3312 (2007/10/03)
The enantioselective hydrolysis of 17 racemic α-substituted arylacetonitriles by Rhodococcus sp. CGMCC 0497 is described. The corresponding (R)-amides and (S)-acids were obtained with excellent enantiomeric excess in most cases. The effect of steric and electronic factors on the outcome of the reactions are discussed here. The results prove that nitrile-converting enzymes are efficient tools for the synthesis of sterically unencumbered chiral α-arylpropionic acids and amides.
Enantioselective biotransformations of racemic α-substituted phenylacetonitriles and phenylacetamides using Rhodococcus sp. AJ270
Wang, Mei-Xiang,Lu, Gang,Ji, Gai-Jiao,Huang, Zhi-Tang,Meth-Cohn, Otto,Colby, John
, p. 1123 - 1135 (2007/10/03)
Rhodococcus sp. AJ270 is an efficient whole-cell system able to catalyze the stereoselective conversions of racemic α-substituted phenylacetonitriles and amides under very mild conditions into enantiopure carboxylic acids and derivatives. The nitrile hydratase involved generally has a broad substrate spectrum against phenylacetonitriles irrespective of the electronic nature of the α-substituent while the amidase is very sensitive to both the electronic and steric factors of the substituent of amides. The overall enantioselectivity of nitrile hydrolysis is mainly determined by the combination of selectivities of nitrile hydratase and of amidase, with the latter being a major contributor. The amidase has high S-enantiocontrol against amides while the nitrile hydratase exhibits low R-selectivity against nitriles. The scope and limitations of this enantioselective biotransformation process are discussed. Copyright (C) 2000 Elsevier Science Ltd.
