Rhodium(I)-Catalyzed Asymmetric Carbene Insertion into B–H Bonds: Highly Enantioselective Access to Functionalized Organoboranes

A unique
rhodium­(I)-catalyzed asymmetric B–H insertion of α-diazo
carbonyl compounds with easily available amine–borane adducts
was achieved using a newly developed C1-symmetric chiral diene as ligand. This first Rh­(I)–carbene-directed
B–H insertion example represents an attractive and promising
approach for synthesis of highly enantio­enriched organoboron
compounds, allowing for the efficient construction of α-boryl
esters and ketones with excellent enantio­selectivities (up to
99% ee) under exceptionally mild conditions.

本研究采用全新开发的C1对称手性双烯配体，成功实现了一类独特的铑(I)催化α-重氮羰基化合物与易得胺-硼加合物的不对称B-H插入反应。这是首例由铑(I)-卡宾导向的B-H插入反应，为合成高对映体富集的有机硼化合物提供了极具吸引力且前景可观的策略；该方法可在极为温和的反应条件下，以优异的对映选择性（最高可达99% ee）高效构建α-硼基酯与酮类化合物。