Triiodide-Mediated δ-Amination of Secondary C−H Bonds
作者:Ethan A. Wappes、Stacy C. Fosu、Trevor C. Chopko、David A. Nagib
DOI:10.1002/anie.201604704
日期:2016.8.16
amination of unactivated, secondary C−Hbonds to form a broad range of functionalized pyrrolidines has been developed by a triiodide (I3−)‐mediated strategy. By in situ 1) oxidation of sodium iodide and 2) sequestration of the transiently generated iodine (I2) as I3−, this approach precludes undesired I2‐mediated decomposition which can otherwise limit synthetic utility to only weak C(sp3)−H bonds. The mechanism
It's a trap! Both epoxides and aziridines substituted by an aryl ketone can be reduced efficiently using visible‐light photoredox catalysts. The radicals generated were trapped by allyl sulfones, and formed α‐branched β‐hydroxy or amino derivatives with high diastereocontrol (see scheme; dtbbpy=4,4′‐di‐tert‐butyl‐2,2′‐bipyridine, ppy=2‐phenylpyridine).