hydrogen; rhodium cation; (S)-(-)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl in methanol Reduction;

1: 87 percent / H2 / (S)-BINAP; RuCl2 / methanol / 11 h / 45 °C / 51716.2 Torr 2: 97 percent / BH3*THF / tetrahydrofuran / 3 h / 20 °C View Scheme

1: 87 percent / H2 / (S)-BINAP; RuCl2 / methanol / 11 h / 45 °C / 51716.2 Torr 2: 97 percent / BH3*THF / tetrahydrofuran / 3 h / 20 °C 3: 98 percent / oxalyl chloride; DMSO; DIPEA / CH2Cl2 / -78 - 20 °C View Scheme

hydrogen; RuCl2; (S)-(-)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl in methanol T=45°C; Reduction; P=51716.2 Torr; 11 h;

1: 87 percent / H2 / (S)-BINAP; RuCl2 / methanol / 11 h / 45 °C / 51716.2 Torr 2: 97 percent / BH3*THF / tetrahydrofuran / 3 h / 20 °C 3: 98 percent / oxalyl chloride; DMSO; DIPEA / CH2Cl2 / -78 - 20 °C 4: 79 percent / n-BuLi / tetrahydrofuran; hexane / -78 - 20 °C 5: 94 percent / H2 / Pd/C / ethyl acetate / 24 h View Scheme