Rhodium‐Catalyzed Branched‐Selective Alkyne Hydroacylation: A Ligand‐Controlled Regioselectivity Switch

Abstract

It's all in the ligand: By choice of the appropriate diphosphine ligand a previously linear-selective alkyne hydroacylation process can be “switched” to be highly branched-selective (see scheme, l=linear, b=branched). Structural data for the ortho-iPr-dppe–rhodium catalyst suggest restricted rotation of the phosphine aryl units may be responsible for the observed selectivity.