Coordination Chemistry and Reactivity of Biaryl Pd Phosphine 1-Azaallyl Complexes

Leslie S.G. Kelley, The University of Western Ontario

Abstract

Structurally responsive ligands (SRLs) are dynamic ligands that can alter coordination mode with a metal centre, to stimulate fundamental organometallic reactions in several catalytic cycles. These dynamic ligand coordination changes can also enable access to unique reaction mechanisms and challenging reaction steps. The Blacquiere group previously synthesized a phosphine 1-azaallyl (P^AzA) ligand, in which the 1-azaallyl (1-AzA) moiety reversibly switches between multiple coordination modes. The previous phenyl-linked P^AzA ligand led to a variety of coordination modes with Pd, however the k¹-P;η³-NCC mode was never observed. In pursuit of accessing the k¹-P;η³-NCC coordination mode, a new P^AzA ligand bearing a biaryl backbone was targeted. The coordination chemistry of the biaryl P^AzA ligand with Pd was explored. Small molecule reactivity with the biaryl Pd P^AzA complex was examined, with the goal of inducing a change in ligand coordination mode. Preliminary catalysis with the biaryl Pd P^AzA complex was assessed.