Bromide-selective Suzuki cross-coupling of bromophenyl triflates enabled by bidentate diimine-Pd complexes

Abstract

Phosphine-ligated palladium complexes have demonstrated high efficacy in achieving chemo-selective Suzuki cross-couplings with bromophenyl triflates, supported by well-established mechanistic frameworks. However, their practical utility is often constrained by high air sensitivity and operational complexity. In contrast, non-phosphine palladium catalysts exhibit improved stability under ambient conditions, thereby facilitating more streamlined experimental workflows. Despite these advantages, non-phosphine ligand systems remain underexplored, and their mechanistic underpinnings lack robust experimental validation. Herein, we report a palladium-diimine-catalyzed protocol enabling exclusive bromide-selective coupling of bromophenyl triflates. This approach presents a potential challenge to the prevailing computational mechanistic framework derived from phosphine-ligated systems. Key features of the protocol also include a broad substrate scope with minimal solvent dependency, low catalyst loading, tolerance to aerobic conditions, and high conversions with minimal byproduct formation. In all, this methodology provides a versatile platform for diaryl triflate synthesis and broadens the ligand toolbox enabling chemo-selective Suzuki cross-coupling.