Highly enantioselective hydrogenation of itaconic acid derivatives with a chiral bisphospholane-Rh(I) catalyst

The new - commercially in multi-kg quantities available - chiral bisphospholane ligand, catA-Sium(R) M, has been successfully used in the Rh(I)catalysed enantioselective hydrogenation of itaconic acid derivatives. Chiral beta-substituted succinic acid derivatives were produced in good to excellent enantioselectivities. Turnover frequencies by up to 40,000 h(-1) have been achieved.