Asymmetric synthesis of the Roche ester and its derivatives by rhodium-INDOLPHOS-catalyzed hydrogenation

Article abstract of DOI:10.1002/adsc.200800209

(S)-3-Hydroxy-2-methylpropionate, known as the Roche ester, and several of its derivatives were successfully synthesized through asymmetric rhodium-catalyzed hydrogenation, using INDOLPHOS (diisopropyl{1-[(S)-3,5-dioxa- 4-phosphacyclohepta[ 2,1-a;3,4-a′]dinaphthalen-4-yl]-3-methyl-2-indolyl} phosphine) as the chiral ligand, in excellent yield and the highest ee reported up to now (TOF over 5500 h^-1 at 25°C; up to 98% ee at -40°C).