A New Method for Production of Chiral 2-Aryloxypropanoic Acids Using Effective Kinetic Resolution of Racemic 2-Aryloxycarboxylic Acids
摘要:
We report a novel method for the preparation of 2-aryloxypropanoic acids by kinetic resolution of racemic 2-aryloxypropanoic acids using enantioselective esterification. The usage of pivalic anhydride (Piv(2)O) as an activating agent, bis(alpha-naphthyl)methanol ((alpha-Np)(2)CHOH) as an achiral alcohol, and (+)-benzotetramisole ((+)-BTM) as a chiral acyl-transfer catalyst enables the effective separation of various racemic 2-aryloxypropanoic acids to afford optically active carboxylic acids and the corresponding esters with high enantioselectivities. Furthermore, theoretical calculations of the transition states required to form the chiral esters successfully proved the enantiomer recognition mechanism of the asymmetric esterification.
Homobenzotetramisole-Catalyzed Kinetic Resolution of α-Aryl-, α-Aryloxy-, and α-Arylthioalkanoic Acids
作者:Xing Yang、Vladimir B. Birman
DOI:10.1002/adsc.200900451
日期:2009.10
Effective kineticresolution of alpha-aryl-, alpha-aryloxy-, and alpha-arylthioalkanoic acids has been achieved via in situ generation of their symmetrical anhydrides and enantioselective alcoholysis in the presence of homobenzotetramisole (HBTM) 3.