Practical, Large-Scale Preparation of Benzoxepines and Coumarins through Rhodium(III)-Catalyzed C–H Activation/Annulation Reactions

Abstract

Herein we disclose the assembly of benzoxepines and coumarins from 2-alkenylphenol precursors using [Cp*RhCl2]2 as the precatalyst and alkynes or carbon monoxide as reacting partners. The preparation of benzoxepines and coumarins can be scaled up to 33 mmol using low catalyst loadings.