Enantioselective synthesis of cyclopropylphosphonates containing quaternary stereocenters using a D2-symmetric chiral catalyst Rh2(S-biTISP)2

Rh-2(SbiTISP)(2)-catalyzed reactions of dimethyl aryldiazomethylphosphonates generate donor/acceptor-substituted rhodium carbenoid intermediates capable of cyclopropanation of styrenes in high yields (85-96%), diastereoselectivity (greater than or equal to98% de), and enantioselectivity (76-92% ee).