Theoretical Studies on the Mechanisms and Origins of Ligand-Controlled Regioselective Hydroacylation of Terminal Alkynes Catalyzed by the Rhodium(I) Complex

Abstract

The rhodium-catalyzed hydroacylation of terminal alkynes provides an efficient strategy for the construction of unsaturated ketones. Density functional theory calculations were carried out to study the mechanisms and understand the origins of the ligand-controlled regioselectivity. The results demonstrate that the reaction follows the classical Chalk−Harrod-type mechanism. Distortion/interaction analyses show that the branched selectivity with L1 ligand stems from the electronic and steric effects, while the linear selectivity with L2 ligand arises from the repulsive interaction between the ligand and substrate. These findings offer crucial insights into the origin of ligand-controlled regioselectivity and furnish valuable guidance for further refining reactions of this nature.