ENANTIOSELECTIVE ORGANIC SYNTHESES USING CHIRAL TRANSITION-METAL COMPLEXES .4. OXYFUNCTIONALIZATION OF ALLYL THIOETHER RUTHENIUM COMPLEXES WITH DIMETHYLDIOXIRANE

Allyl thioether complexes [CpRu(P-P)(SRR')]PF6 (P-P = Ph2PCH2PPh2 (dpp m), Ph2PC2H4PPh2 (dppe), R = Me, Et, Ph, R' = 3-propenyl, 3-cyclohexen yl, 2-methyl-2-buten-4-yl) and [CpRu(chir)(SRR')]PF6 (chir = (S,S)-Ph2 PCHMeCHMePPh2, R = Me, CH2Ph, R' = 2-methyl-2-buten-4-yl) are obtained from the corresponding thiolate complexes by reaction with the approp riate allyl bromide. Careful oxidation with dimethyldioxirane (DMD) ga ve the allyl sulfoxide complexes [CpRu(P-P)(MeS(O)CH2CH=CH2)]PF6 (P-P = dppm, dppe). Double oxidation to the corresponding sulfinylmethyl ep oxide complexes can be readily achieved with an excess of DMD. Oxidati on of the chir complexes proceeds with only moderate diastereoselectiv ity. The structure of the (R, R/S, S) diastereomer of [CpRu(dppm)(MeS( O)CH2CHCH2O)]PF6 was determined: monoclinic space group P2(1)/c (No. 1 4), a = 11.21(2), b = 16.762(9), c = 18.45(4) Angstrom, beta = 94.4(1) degrees, Z = 4. For a representative example, the decomplexation of th e sulfoxide-epoxide ligand by sodium iodide in acetone was demonstrate d.