MULTIPLE BONDS BETWEEN MAIN-GROUP ELEMENTS AND TRANSITION-METALS .77. CONDENSATION-REACTIONS OF METHYLTRIOXORHENIUM(VII) WITH CATECHOLS AND AROMATIC THIOLS

The title compound methyltrioxorhenium (VII) reacts with catechols to yield complexes of the formula CH3Re(O)2(1,2-O2C6R4) (<2>) that are fully characterized as pyridine adducts 3. Conducting these reactions in the presence of nucleophiles, e.g., halides, gives the hexacoordinate anions [CH3Re(O)2(1,2-O2C6R4)(X)]- of compounds 4a-c (X = Cl, Br, I) in high yields. Based upon spectroscopic data, the oxo ligands occupy cis positions and the halide ligand occupies trans positions with respect to the methyl group of these novel five-membered d0 rhenacycles. The rhenium (V) species "CH3ReO2", prepared in situ from 1 by reduction with (polymer bound) triphenylphosphane, reacts with phenanthrenequinone in the presence of pyridine to give the neutral hexacoordinate complex CH3Re(O)2(9,10-O2C14H8)(NC5H5) (5), with the quinone ligand being present in the reduced form as catecholate while the rhenium is in the oxidation state VII. Reaction of 1 with thiophenol gives initially the rhenium (VII) complex CH3ReO(SC6H5)4 (6), which upon heating undergoes intramolecular elimination of diphenyl disulfide, C6H5SSC6H5, to give the dinuclear rhenium(V) complex [CH3ReO(mu-SC6H5)(SC6H5)2 (7; X-ray diffraction study). Condensation of 1 with benzene-1,2-dithiol gives the rhenium(VII) complex CH3ReO(1,2-S2C6H4)2 (8).