Isothiourea‐Catalyzed Atropselective Acylation of Biaryl Phenols via Sequential Desymmetrization/Kinetic Resolution
作者:Elizabeth S. Munday、Markas A. Grove、Taisiia Feoktistova、Alexander C. Brueckner、Daniel M. Walden、Claire M. Young、Alexandra M. Z. Slawin、Andrew D. Campbell、Paul Ha‐Yeon Cheong、Andrew D. Smith
DOI:10.1002/anie.201916480
日期:2020.5.11
chiral ligands and catalysts. Despite their utility few simple catalytic methods are available for their synthesis in high enantiopurity. Herein the atropselective acylation of a range of symmetric biaryl diols is investigated using isothiourea catalysis. Studies on a model biaryl diol substrate shows that the high product er observed in the process is a result of two successive enantioselective reactions
Enantioselective synthesis of axially chiral sulfur-containing biaryl derivatives through the electrophilic sulfenylation of biaryl phenols has been achieved for the first time. This catalyticasymmetric system, which involves sequential desymmetrization and kinetic resolution, is enabled by a combination of a novel 3,3′-disubstituted BINOL-derived selenide catalyst and an achiral sulfonic acid. Control experiments
The axiallychiral biaryls 2 were obtained in high enantioselectivity by desymmetrization of the σ-symmetric biaryl diacetates 1 by lipase-catalyzed hydrolysis.
achieved with a silylium-ion-like silicon electrophile paired with a List-type imidodiphosphorimidate (IDPi). The initial enantioinduction of the desymmetrization is further enhanced by a downstream kineticresolution that kinetically selects the monosilylated minor enantiomer to form the corresponding bissilylated diol (see Scheme; TBS=tert-butyldimethylsilyl).