ORGANIC-REACTIONS UPON DIMETALLATED OLEFINS - INSERTION REACTIONS AT BOTH ENDS OF THE ALKYNE IN THE DIRHENIUM COMPLEX RE(CO)4[TRANS-MU-HC=C(CO2ME)]RE(CO)4(NCME)

The reaction of (OC)4Re[trans-mu-HC=C(CO2Me)Re(CO)4(MeCN), 1, with CS2 yielded the new complex (OC)4Re[(E)-HC=C(CO2Me)CS2]Re(CO)4,2, in 78% yield by displacement of the NCMe ligand and the addition and insertion of a CS2 molecule into one of the Re-C bonds in 1. The CS2 grouping is chelated to the rhenium atom through the sulfur atoms. Reaction of 2 with pyridine N-oxide yielded two new compounds (OC)4Re[OC(H)C(CO2Me)C(S)S]Re(CO)4, 3a, in 97 % yield and an isomer Re2(CO)8[mu-SC(S)C(CO2Me)C(H)O], 4a, in 3 % yield. The related sulfur derivatives (OC)4Re[SC(H)C(CO2Me)CS2]Re(CO)4, 3b, 50% yield, and Re2(CO)8(mu-SC(S)C(CO2Me)C(H)S], 4b, 6% yield, were obtained from the reaction of 2 with ethylene sulfide at 25-degrees-C for 3 h. Compounds 3a,b will isomerize to 4a,b in quantitative yields. Compounds 3a,b were formed by the insertion of the heteroatom O or S into the Re-C bond in 2. The isomers 4a,b were formed by release of the coordinated carboxylate group in 3a,b and the formation of a bridging coordination between the rhenium atoms by one of the sulfur atoms of the CS2 grouping. Two products (OC)4Re[C3H2(CO2Me)(CO2Et)C(S)S]Re(CO)4, 5, 5%, and Re2(CO)8[SC(S)C(CHCHCO2Et)C(OMe)O], 6,52%, were obtained from the reaction of 2 with ethyl diazoacetate. Compound 6 was also obtained from 5 in 28% yield by heating to 90-degrees-C. Compounds 2, 3b, 4a, 5, and 6 were characterized by single crystal X-ray diffraction analyses. Crystal data: (for 2) space group C2/c, a = 18.651(3) angstrom, b = 11.513(3) angstrom, c = 17.952(2) angstrom, beta = 97.54(1)degrees, Z = 8, 2320 reflections, R = 0.028; (for 3b) space group = P1BAR, a = 12.363(2) angstrom, b = 13.880(3) angstrom, c = 5.973(1)angstrom, alpha = 93.09(2)degrees, beta = 101.06()degrees, gamma = 77.81(1)degrees, Z = 2126 reflections, R = 0.020; (for 4a) space group = P1BAR, a = 10.784(2) angstrom, b = 12.337(2) angstrom, c = 7.2712(9) angstrom, alpha = 95.30(1)degrees, beta = 92.55(1)degrees, gamma = 97.52(1)degrees, Z = 2, 1906 reflections, R = 0.023; (for 5) space group = P1BAR, a = 13.184(2) angstrom, b = 15.658(2) angstrom, c = 6.5470(8) angstrom, a = 100.26(1)degrees, beta= 101.31(1)degrees, gamma = 65.16(1)degrees, Z = 2, 2253 reflections, R = 0.020; (for 6) space group = Pbca, a = 14.800(3) angstrom, b = 12.312(3) angstrom, c = 26.308(4) angstrom, Z = 8, 2070 reflections, R = 0.031.