Tuning N-heterocyclic carbenes in T-shaped Pt(II) complexes for intermolecular C-H bond activation of arenes

Angew Chem Int Ed Engl. 2012 Apr 16;51(16):3936-9. doi: 10.1002/anie.201200070. Epub 2012 Mar 8.

Abstract

Small change matters: T-shaped Pt(II) complexes with less flexible substituents, than, for example, isopropyl or tert-butyl groups, on N-heterocyclic carbene (NHC) ligands allow for C-H bond activation reactions of aromatic compounds (see scheme; BAr(f)(4)(-) =tetrakis[(3,5-trifluoromethyl)phenyl]borate; F yellow, Pt red). NHC substituents that are not highly branched prevent agostic interactions and reduce the barriers to achieve the C-H bond cleavage.