188016-03-7Relevant academic research and scientific papers
One-pot kinetic resolution-Mitsunobu reaction to access optically pure compounds, using silver salts in the substitution protocol
Raval, Hiten B.,Bedekar, Ashutosh V.
, p. 21238 - 21243 (2020)
A practical method is developed to access chiral arylalkyl carbinols with a high yield from racemic alcohols. A one-pot enzyme mediated Kinetic Resolution followed by Mitsunobu esterification of the unreacted enantiomer of alcohol with metal acetate results in a nearly complete formation of chiral acetate. Substitution with AgOAc was found to be the most efficient, and the use of sub stoichiometric amounts of AgNO3 and excess of NaOAc affords comparable results; the protocol was further extended to introduce azide as a nucleophile.
Separation of enantiopure m-substituted 1-phenylethanols in high space-time yield using Bacillus subtilis esterase
Zheng, Gao-Wei,Liu, Xu-Yun,Zhang, Zhi-Jun,Tian, Ping,Lin, Guo-Qiang,Xu, Jian-He
, p. 20446 - 20449 (2013/11/06)
A recombinant Bacillus subtilis esterase (BsE) expressed in E. coli was found to exhibit excellent enantioselectivity (E was always greater than 100) towards m-substituted 1-phenylethanol acetates in the enantioselective hydrolysis reaction. An explanation for the high enantioselectivity observed towards these substrates was provided by molecular modeling. Moreover, the BsE also showed strong tolerance towards a high concentration of m-substituted 1-phenylethanol acetates (up to 1 M). Based on these excellent catalytic properties of BsE, a kind of m-substituted 1-phenylethanols, (R)-1-(3-chlorophenyl)ethanol, was efficiently synthesized in space-time yield of 920 g per L per day and 97% ee, indicating that the BsE was considered as a potentially ideal and promising biocatalyst for large-scale production of optically active m-substituted 1-phenylethanols. The Royal Society of Chemistry 2013.
Synthesis of chiral aromatic alcohols: Use of new C2-symmetric RhIIICp*, RuII(cymene), or RuII(benzene) complexes containing chiral diaminocyclohexane ligand as asymmetric transfer hydrogenation catalyst
Montalvo-Gonzalez, Ruben,Chavez, Daniel,Aguirre, Gerardo,Parra-Hake, Miguel,Somanathan, Ratnasamy
experimental part, p. 2737 - 2746 (2009/12/06)
Twelve chiral secondary alcohols were synthesized by asymmetric transfer hydrogenation (ATH) using C2-symmetric bis(sulfonamide) ligand (2) derived from (1R,2R)-cyclohexane-1,2-diamine and complexed with [RhCl 2CP*]2, [RuCl2(cymene)] 2, or [RuCl2(benzene)]2 and then used in situ in the reduction of prochiral ketones. The alcohols were obtained in 85-99% yield and 90-99% enantioselectivity with isopropanol as the hydrogen source. Two-fold rate enhancement and better yields were achieved (88-99%) with 80-99% enantioselectivity using the complex [RhCl2CP*] 2 and aqueous sodium formate as the hydrogen source.
Enantioselective acylation of primary and secondary alcohols catalyzed by lipase QL from Alcaligenes sp.: A predictive active site model for lipase QL to identify which enantiomer of an alcohol reacts faster in this acylation
Naemura, Koichiro,Murata, Masaki,Tanaka, Rie,Yano, Masashi,Hirose, Keiji,Tobe, Yoshito
, p. 3285 - 3294 (2007/10/03)
Lipase QL (from Alcaligenes sp.)-catalyzed acylation of alcohols using isopropenyl acetate as the acylating agent in diisopropyl ether converted preferentially primary alcohols with an S configuration and secondary alcohols with an R configuration into the corresponding homochiral acetates. On the basis of observed enantiomer selectivities, a predictive active site model for lipase QL is proposed for identifying which enantiomer of a primary or a secondary alcohol reacts faster in this acylation. Copyright (C) 1996 Published by Elsevier Science Ltd.
ASYMMETRIC ACYLATION OF ALCOHOLS IN THE PRESENCE OF CHIRAL TERTIARY AMINES
Potapov, V. M.,Dem'yanovich, V. M.,Khlebnikov, V. A.,Koval'skaya, S. S.
, p. 1602 - 1606 (2007/10/02)
The asymmetric acylation of secondary alcohols with acetic anhydride in the presence of chiral tertiary amines, synthesized from S-(-)-α-phenylethylamine, was investigated.The optical yield of the obtained alcohols was not greater than 2.4percent.It was established that in the presence of S-(-)-N,N-dimethyl-α-phenylethylamine the unreacted alcohol is rich in the S isomer.On the basis of this relationship the S configuration was proposed for (-)-4-iodo-, (-)-4-chloro-, and (-)-3-nitrophenylehanols.
