Addition compounds of MoO2Cl2 with chiral sulfoxides. First molecular structures of dioxomolybdenum complexes bearing chiral non-racemic sulfoxide as ligand

MoO2Cl2(L)2 [L = (R)-(+)-methyl-p-tolylsulfoxide (R-MeTolSO) (1), methyl-p-tolylsulfoxide (MeTolSO) (2), 2-benzenesulfinyl-1,1-diphenylethanol (BSDPE) (3), 1-benzenesulfinyl-2-methyl-2-propanol (BSMP) (4), benzenesulfinylmethyl 4-methylphenyl ketone (BSMMPK) (5)], and MoO2Cl2(L) [L = BSDPE (6), BSMP (7), BSMMPK (8), (S,S)-bis(p-tolylsulfinyl)methane (S,S-TolSOCH2SOTol) (9), bis(methylsulfinyl)methane (MeSOCH2SOMe) (10), bis(phenylsulfinyl)methane (PhSOCH2SOPh) (11)] have been synthesized by reacting a solution of MoO2Cl2(H2O)2 in diethyl ether with the corresponding ligand. The crystal and molecular structures of 1, 2, and 9 have been established by X-ray diffraction analysis. The ability of 1 and 9 as catalysts for the enantioselective reduction of sulfoxides to sulphides and the oxidation of sulphides to sulfoxides has been examined.