Combined Dynamic Kinetic Resolution and C-H Functionalization for Facile Synthesis of Non-Biaryl-Atropisomer-Type Axially Chiral Organosilanes.
Zhao LiXu WangYu-Ming CuiJun-Han MaLi-Lei FangLu-Lu HanQin YangZheng XuLi-Wen XuPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2021)
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.