New Bisphosphine Ligands for Palladium-Catalyzed Desymmetrization of meso-Cyclopent-2-en-1,4-diol Biscarbamate

A new class of bisphosphine ligands (5, 6) with a cyclo­butane backbone have been designed and synthesized on the basis of a privileged C2 scaffold of head-to-head coumarin dimer, among which ligand 5a was found to show excellent activity and enantioselectivity in Pd-catalyzed desymmetrization of the biscarbamate of meso-cyclopent-2-en-1,4-diol, affording oxazolidin2-one in up to 90% yield with 97% ee.