A Green and Aerobic Micellar Suzuki–Miyaura Coupling with Low Pd Loading Enabled by a Lignin-Derived Surfactant

Micellar catalysis has emerged over the past decade as an appealing strategy for carrying out organic reactions in water, allowing high yields under mild and environmentally friendly conditions. Notable progress in this area has been achieved by Lipshutz and co-workers through the introduction of “designer surfactants”, such as the tocopherol-derived TPGS-750-M and the more recent Savie surfactant, both capable of efficiently promoting a broad range of transformations in aqueous micelles. However, the presence of the polyoxyethylene chain in TPGS-750-M restricts its complete biodegradability. In a previous study, we introduced a new class of surfactants (GVn) built on a vanillic acid scaffold derived from lignin degradation. These amphiphilic molecules are obtained from renewable feedstocks via esterification with long-chain alcohols, followed by functionalization with glycerol carbonate. Despite containing only two hydroxyl groups, they readily self-assemble into micelles and exhibit low critical micelle concentrations. In the present work, a series of lignin-derived surfactants was investigated in the Suzuki cross-coupling reaction to evaluate their performance in micellar catalysis. Among them, GV8, characterized by a C8 alkyl chain, proved to be the most effective. The reaction scope was explored under optimized conditions by coupling aryl bromides with boronic acids in a 2% aqueous GV8 micellar solution, employing a palladium catalyst at 0.25% loading and TEA as the base.