sodium tetrahydroborate; (salen)Mn in ethanol; benzene T=20°C; 15 h;

1: 2.) Cu(OAc)2, conc. aq. NH3, air / 1.) THF, Et2O, RT, 12 h, 2.) THF, Et2O, MeOH, 10 min 2: 62 percent / <N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminato> manganese(III) chloride, di-tert-butyl peroxide, NaBH4 / toluene; ethanol / 12 h / Ambient temperature View Scheme