Synthesis of Axially Chiral Styrenes through Pd‐Catalyzed Asymmetric C−H Olefination Enabled by an Amino Amide Transient Directing Group
Hong Song, Ya Li, Qi‐Jun Yao, Liang Jin, Lei Liu, Yanhua Liu, Bing‐Feng Shi
Abstract
Abstract The atroposelective synthesis of axially chiral styrenes remains a formidable challenge due to their relatively lower rotational barriers compared to the biaryl atropoisomers. Herein, we describe the construction of axially chiral styrenes through Pd II ‐catalyzed atroposelective C−H olefination, using a bulky amino amide as a transient chiral auxiliary. Various axially chiral styrenes were produced with good yields and high enantioselectivity (up to 95 % yield and 99 % ee ). Carboxylic acid derivatives of the resulting axially chiral styrenes showed superior enantiocontrol over the biaryl counterparts in Co III ‐catalyzed enantioselective C(sp 3 )−H amidation of thioamide. Mechanistic studies suggest that C−H cleavage is the enantioselectivity‐determining step.