Enantioselective Cu-catalyzed double hydroboration of alkynes to access chiral gem-diborylalkanes
Shengnan Jin, Jinxia Li, Kang Liu, Wei‐Yi Ding, Shuai Wang, Xiujuan Huang, Xue Li, Peiyuan Yu, Qiuling Song
Abstract
Chiral organoborons are of great value in asymmetric synthesis, functional materials, and medicinal chemistry. The development of chiral bis(boryl) alkanes, especially optically enriched 1,1-diboron compounds, has been greatly inhibited by the lack of direct synthetic protocols. Therefore, it is very challenging to develop a simple and effective strategy to obtain chiral 1,1-diborylalkanes. Herein, we develop an enantioselective copper-catalyzed cascade double hydroboration of terminal alkynes and highly enantioenriched gem-diborylalkanes were readily obtained. Our strategy uses simple terminal alkynes and two different boranes to construct valuable chiral gem-bis(boryl) alkanes with one catalytic and one ligand pattern, which represents the simplest and most straightforward strategy for constructing such chiral gem-diborons.