“On‐Water”‐Promoted <i>C</i>‐Alkylation of Indoles with 2‐Aryl‐3‐nitro‐2<i>H</i>‐chromenes under Catalyst‐Free Conditions

Abstract

Abstract An environmentally benign method for the synthesis of indolyl(nitro)chromans from indoles and 2‐aryl‐3‐nitro‐2 H ‐chromenes under catalyst‐free conditions by use of an “on‐water” concept is described. The salient features of the methodology are its clean reaction conditions, the eco‐friendly medium, and the easy isolation and excellent diastereoselectivities of the products.(© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2009)