Pd/C in Propylene Carbonate: A Sustainable Catalyst-Solvent System for the Carbonylative Suzuki-Miyaura Cross-Coupling Using N-Formylsaccharin as a CO Surrogate

This work documents the first Pd/C-catalyzed carbonylative Suzuki-Miyaura cross-coupling of aryl iodides with N-formylsaccharin as a CO surrogate. In contrast to previous reaction protocols, which make use of toxic and hazardous solvents, the reaction could be advantageously performed in propylene carbonate as an environmentally benign and sustainable polar aprotic solvent. A range of biaryl ketones, including (4-methoxyphenyl)(3,4,5-trimethoxyphenyl) methanone, an antineoplastic belonging to the phenstatin family, could be synthesized under cocatalyst-free, additive-free and ligand-free conditions. The Pd/C could be recycled up to five times under CO surrogacy with only a marginal decrease in catalytic activity. The reaction could also be scaled up to gram-scale syntheses.