Cooperative Transition Metal/Lewis Acid Bond-Activation Reactions by a Bidentate (Boryl)­imino­methane Complex: A Significant Metal–Borane Interaction Promoted by a Small Bite-Angle LZ Chelate

The synthesis of a three-coordinate Pt–borane complex featuring a bidentate “LZ” (boryl)­imino­methane (BIM) ligand is reported. Unlike other LZ-type borane ligands featuring a single-donor buttress, the small bite angle enforced by the BIM ligand is shown to promote a significant metal–borane reverse-dative σ-interaction akin to multiply strapped metalloboratranes. The steric accessibility of the reactive Pt → B bond fostered by the BIM ligand allows for a rich reactivity profile toward small molecules that exploit metal–borane cooperative effects. The unligated (boryl)­imino­methane BIM is also synthetically accessible and functions as a Frustrated Lewis Pair (FLP). The ability of the free BIM to effect bond activation reactions is contrasted with the behavior seen in the corresponding platinum-bound complexes.