Asymmetric catalyses. XXXIII. New optically active phospholanes derived from tartaric acid

Article abstract of DOI:10.1016/S0022-328X(00)99768-7

New optically active phospholanes derived from tartaric acid were synthesized by cyclization of 1,4-ditosylates with NaPH₂ and Li₂PPh. Alkylation of these phosphines led to stable phosphonium salts which gave the alkylated derivatives on treatment with bases. Phospholanes containing Cl, OMe, or NMe₂ substituents at phosphorus were prepared and characterized. Mn and Rh complexes with alkylphospholane ligands were synthesized. Rh phospholane catalysts gave optical inductions up to 16.8% ee in the enantioselective hydrogenation of (Z)-α-(N-acetamido) cinnamic acid.