Intramolecular Buchner Reaction: Experimental and Theoretical Comparison of the Effect of the Carbene Substituent on the Chemoselectivity

Abstract

AbstractThe intramolecular Buchner reaction is a powerful transformation able to dearomatize benzenic rings. However, the competitive C−H insertion of the carbene moiety into benzylic positions still remains a limitation, and the reasons governing this uncomplete chemoselectivity are poorly understood. The carbene substitution, in particular, has been observed to influence the selectivity strongly, though the currently proposed explanation relying on the electrophilicity of the metallocarbene hardly describes some experimental results reported in the literature. In this article, we present our experimental observations of intramolecular rhodium‐catalyzed Buchner reactions, combined with DFT calculations on selected carbene substituents, to propose a complementary explanation for the observed chemoselectivity modification.