Gold- and Silver-Catalyzed Tandem Amination/Ring Expansion of Cyclopropyl Methanols with Sulfonamides as an Expedient Route to Pyrrolidines
作者:Weidong Rao、Philip Wai Hong Chan
DOI:10.1002/chem.200801242
日期:2008.11.17
An efficient syntheticroute to pyrrolidines that relies on AuCl/AgOTf-catalyzed tandem amination/ringexpansion of substituted cyclopropyl methanols with sulfonamides is reported herein. The reactions proceed rapidly at 100 degrees C with catalyst loadings as low as 2 mol % and produce the pyrrolidine products in yields of 30-95 %. The method was shown to be applicable to a broad range of cyclopropyl
Very longchainfattyacids are isolated from many different natural sources. However their unsaturated and particularly their diunsaturated derivatives with a Δn,n+4 pattern are almost exclusively encountered in marine organisms, until we found some derivatives in the botanical family of the Annonaceae. In this letter we present a very efficient synthesis of this family of products based on the new