Rh-catalyzed C–C bond cleavage by transfer hydroformylation

作者：Stephen K. Murphy, Jung‐Woo Park, Faben A. Cruz, Vy M. Dong · 发表于：Science · 年份：2015 · DOI：10.1126/science.1261232 · 被引用次数：254 · 研究领域：Asymmetric Hydrogenation and Catalysis、Organometallic Complex Synthesis and Catalysis、Carbon dioxide utilization in catalysis

The dehydroformylation of aldehydes to generate olefins occurs during the biosynthesis of various sterols, including cholesterol in humans. Here, we implement a synthetic version that features the transfer of a formyl group and hydride from an aldehyde substrate to a strained olefin acceptor. A Rhodium (Xantphos)(benzoate) catalyst activates aldehyde carbon-hydrogen (C-H) bonds with high chemoselectivity to trigger carbon-carbon (C-C) bond cleavage and generate olefins at low loadings (0.3 to 2 mole percent) and temperatures (22° to 80°C). This mild protocol can be applied to various natural products and was used to achieve a three-step synthesis of (+)-yohimbenone. A study of the mechanism reveals that the benzoate counterion acts as a proton shuttle to enable transfer hydroformylation.