Asymmetric Hydroxylation, Epoxidation, and Sulfoxidation Catalyzed by Vaulted Binaphthyl Metalloporphyrins

A chiral, vaulted binaphthyl porphyrin (1) has been prepared from 5α,10β,15α,20β-tetrakis(o-amino-phenyl)porphyrin and (R)-(+)-2,2′-dimethoxy-1,1′-bi-6-naphthoyl chloride in 79% yield. Asymmetric oxygenations of alkanes, alkenes, and alkyl sulfides were catalyzed with the chloroiron(III) and chloromanganese(III) complexes of 1 with good yields and high stereoselectivities. The first catalytic asymmetric hydroxylations are reported for l-Fe^IIICl with enantiomeric excesses in the range of 40-72%. The corresponding manganese catalyst, l-Mn^IIICl, gave much lower enantiomeric excesses. For catalytic asymmetric epoxidations, enantiomeric excesses were in the range of 20-72%. Prochiral alkyl sulfides gave sulfoxides with 14-48% ee with l-Fe^IIICl.