Backbone deprotonation defines a hidden decomposition pathway of diphosphine ligands

Abstract

Diphosphine ligands are ubiquitous partners in synthetic chemistry, enabling tuneable reactivity and selectivity. Here, we identify an overlooked decomposition pathway: base-induced deprotonation of an ethylene diphosphine carbon backbone to give a strained metallabicycle. The instability of this scaffold, reflected in a short half-life and decomposition even during routine filtration, has implications for diphosphine–metal coordination chemistry and catalysis under basic conditions.