Rhodium-catalyzed asymmetric hydrogenation with self-assembling catalysts in propylene carbonate

Propylene carbonate (PC) may serve as a perfect solvent in the asymmetric rhodium-catalyzed hydrogenations of functionalized olefins like methyl N-acetamido acrylate and methyl α-(Z)-N-acetamido cinnamate using chiral self-assembling catalysts. In several examples superior reaction rates and enantioselectivities were found in comparison to the use of dichloromethane, commonly used as a solvent. The performance of the catalyst is influenced by the bulk of the phosphorus ligands. A 31P NMR spectrum registered in PC showed the same self-assembling architecture as found in other nonprotic solvents.