Title
Carbene-catalyzed atroposelective synthesis of axially chiral styrenes
Author
Jia-Lei Yan, Rakesh Maiti, Shi-Chao Ren, Weiyi Tian, Tingting Li, Jun Xu, Bivas Mondal, Zhichao Jin & Yonggui Robin Chi
Year
2022
Journal
Nature Communications
Abstract
Axially chiral styrenes bearing a chiral axis between a sterically non-congested acyclic alkene and an aryl ring are difficult to prepare due to low rotational barrier of the axis. Disclosed here is an N-heterocyclic carbene (NHC) catalytic asymmetric solution to this problem. Our reaction involves ynals, sulfinic acids, and phenols as the substrates with an NHC as the catalyst. Key steps involve selective 1,4-addition of sulfinic anion to acetylenic acylazolium intermediate and sequential E-selective protonation to set up the chiral axis. Our reaction affords axially chiral styrenes bearing a chiral axis as the product with up to > 99:1 e.r., > 20:1 E/Z selectivity, and excellent yields. The sulfone and carboxylic ester moieties in our styrene products are common moieties in bioactive molecules and asymmetric catalysis.
Full Article
Instrument
P-1030
Keywords
NHC, chiral, catalysis