Solvent-Controlled Bifurcated Cascade Process for the Selective Preparation of Dihydrocarbazoles or Dihydropyridoindoles
作者:Dong-Liang Mo、Donald J. Wink、Laura L. Anderson
DOI:10.1002/chem.201403268
日期:2014.10.6
A solvent‐controlled cascadeprocess has been identified for the dual purpose of the preparation of either dihydrocarbazoles or dihydropyridoindoles from identical N‐aryl‐α,β‐unsaturated nitrones and electron‐deficient allene starting materials. These reactions proceed smoothly under mild metal‐free conditions affording a range of two types of skeletally distinct indole‐based heterocycles in high yield
Unlike phosphonium ylides used extensively for C═C bond formation, herein we disclose the direct use of phosphonium salts for site-selective alkylation to p-quinols via a 5-membered betaine-type intermediate. This strategy provides a novel and general approach for the synthesis of α-(m-aminoaryl) esters, amides and ketones under ambient conditions. The reaction proceeds through in situ generation of