Combined Dynamic Kinetic Resolution and C−H Functionalization for Facile Synthesis of Non‐Biaryl‐Atropisomer‐Type Axially Chiral Organosilanes
Zhao Li, Xu Wang, Yu‐Ming Cui, Junhan Ma, Li‐Lei Fang, Lulu Han, Qin Yang, Zheng Xu, Li‐Wen Xu
Abstract
Although asymmetric C-H functionalization has been available for the synthesis of structurally diverse molecules, catalytic dynamic kinetic resolution (DKR) approaches to change racemic stereogenic axes remain synthetic challenges in this field. Here, a concise palladium-catalyzed DKR was combined with C-H functionalization involving olefination and alkynylation for the highly efficient synthesis of non-biaryl-atropisomer-type (NBA) axially chiral oragnosilanes. The chemistry proceeded through two different and distinct DKR: first, an atroposelective C-H olefination or alkynylation produced axially chiral vinylsilanes or alkynylsilanes as a new family of non-biaryl atropisomers (NBA), and second, the extension of this DKR strategy to twofold o,o'-C-H functionalization led to the multifunctional axially chiral organosilicon compounds with up to >99 % ee.