Challenging the Scope of Micellar Catalysis: Efficient Suzuki-Miyaura Couplings in Aqueous Dispersions

Green chemistry has emerged as a key driver in the transformation of the chemical industry, with modern synthetic methodologies increasingly focused on reducing energy consumption, waste production, and resource depletion. A major contributor to waste in complex chemical processes is the use of high volumes of organic solvents during synthesis and purification. Despite the environmental appeal of water as a medium, the hydrophobicity of most organic reactants poses a limit to the replacement of organic solvents with aqueous environments. Micellar catalysis offers a promising solution to this issue by enabling reactions on hydrophobic compounds in water with the use of surfactants. However, the performance of micellar reactions depends strongly on the surfactants employed and on the physical state of the reactants used, and small amounts of organic co-solvents are often required to stabilize the reactants and obtain good yields and reproducibility. Here we show that a specific mixture of food-grade lecithin and the industrial surfactant Tween 80 enables efficient micellar Suzuki-Miyaura couplings on substrates with limited solubility both in water and in common organic solvents, with no need of co-solvent addition. In particular, we report successful functionalization of almost insoluble pigments, relevant for the dye and printed (opto)electronic industry, at mild conditions and with results comparable to previously reported methods. Moreover, we explore the application of the same approach for the synthesis of representative semiconducting polymers. These findings highlight the potential of optimized micellar catalysis to go beyond the capability of carrying out reactions on hydrophobic molecules in water and extend even to substrates that are challenging to react in organic solvents.