An efficient, chemoselective homologation of Weinreb amides to the corresponding variously substituted [small alpha]-oxyketones has been developed via the addition of lithiated [small alpha]-oxygenated species. This one-step, experimentally easy, high yielding protocol...
Gold-Catalyzed Oxidative Rearrangement of Homopropargylic Ether via Oxonium Ylide
作者:Mei Xu、Tian-Tian Ren、Chuan-Ying Li
DOI:10.1021/ol302238t
日期:2012.9.21
Syntheticallyuseful α,β-unsaturated carbonyl compounds were obtained from gold-catalyzed oxidative rearrangement of homopropargylic ether under mild reaction conditions. Gold carbenoid and oxonium ylide are proposed as key intermediates.
Treatment of tertiary cyclopropylamines with cerium(IV) ammonium nitrate (CAN) gave ring-opened ketones and/or bicyclic secondary amines via an oxidative cyclopropane cleavage followed by a hydrogen abstraction or 5-exo radical cyclization: an N-benzyl group plays a crucial role in these reactions.