A Pd(ii)-catalyzed denitrative alkyne annulation reaction for the synthesis of cyclopenta[b]chromanes

Abstract

An unprecedented Pd(II)-catalyzed annulation reaction is developed for the synthesis of cyclopenta[b]chromane derivatives bearing a tertiary hydroxyl group. In this reaction, readily available 2-(2-nitrovinyl)phenols are annulated with two molecules of disubstituted alkynes via denitration to afford a wide range of annulated products. Additionally, one novel In(III)-catalyzed dehydroxylative 1,2-phenyl shift reaction is also performed on some of the synthesized chromane derivatives to afford cyclopentenones.