Enantioselective Formal α-Methylation and α-Benzylation of Aldehydes by Means of Photo-organocatalysis
作者:Giacomo Filippini、Mattia Silvi、Paolo Melchiorre
DOI:10.1002/anie.201612045
日期:2017.4.10
photoexcitation of enamines to trigger the formation of reactive carbon-centered radicals from iodosulfones, while the ground-state chiral enamines provide effective stereochemical control over the radical trapping process. The phenylsulfonyl moiety, acting as a redox auxiliary group, facilitates the generation of radicals. In addition, it can eventually be removed under mild reducing conditions to reveal methyl
本文详细描述了醛与(苯磺酰基)烷基碘的光化学有机催化对映选择性α-烷基化。该化学依赖于烯胺的直接光激发来触发碘砜形成以碳为中心的反应性自由基,而基态手性烯胺则对自由基捕获过程提供有效的立体化学控制。苯磺酰基部分作为氧化还原辅助基团,促进自由基的产生。此外,它最终可以在温和的还原条件下被去除,以露出甲基和苄基。