A Green and Low Pd Loading Micellar Suzuki-Miyaura Coupling Driven by a Lignin-Derived Surfactant

Micellar catalysis has emerged in the last decade as an attractive strategy for performing organic reactions in water, enabling high yields under mild and environmentally friendly conditions. Significant advances in this field have been achieved by Lipshutz and coworkers through the development of “designer surfactants”, such as the tocopherol-derived TPGS-750-M and the more recent Savie surfactant, which efficiently promote a wide range of transformations in aqueous micelles. However, the polyoxyethylene chain of TPGS-750-M limits its full biodegradability. In a previous study, we reported a new family of surfactants (GVn) based on a vanillic acid scaffold obtainable from lignin degradation. These amphiphiles are prepared from renewable feedstocks through esterification with long-chain alcohols followed by functionalization with glycerol carbonate. Despite containing only two hydroxyl groups, they readily form micelles and display low critical micelle concentrations. In this study, we evaluated a series of ligninderived surfactants in the Suzuki cross-coupling reaction to assess their effectiveness in micellar catalysis. GV8, a surfactant with a C8 alkyl chain length, was found to be the most effective. The reaction scope was investigated under the optimized conditions by reacting aryl bromides with boronic acids in a 2% aqueous GV8 micellar solution, using a Palladium catalyst at 0.25 % loading, and TEA as base.