Transformation of alkenyl-N-arylthioamido ligands into quinoline-2-thiolate ligands in dirhenium carbonyl complexes

Irradiation of the alkenyl-N-arylthioamide complexes Re(CO)[sub 4][(E)-HC=C(CO[sub 2]Me)C=N-(C[sub 6]H[sub 4]-p- R)S] Re(CO)[sub 4], 1a-c, R = H, Me, Cl, in the presence of iodine yielded a mixture of four products: Re[sub 2](CO)[sub 7][[mu]-2-S-3-CO[sub 2]Me-6-RNC[sub 9]H[sub 4]] ([mu]-I), 2a-c, R = H, Me, Cl; Re(CO)[sub 4][(E)-HC=C-(CO[sub 2]Me) C=N(C[sub 6]H[sub 4]-p-R)S]Re[sub 2](CO)[sub 7]([mu]-I), 3a-c, R = H, Me, Cl;Re(CO)[sub 4][(E)-HC=C(CO[sub 2]Me)C-(NHC[sub 6]H[sub 4]-p- R)=S] B Re(CO)[sub 4](I), 4a-c, R = H, Me, Cl;Re(CO)[sub 4](2-S-3-CO[sub 2]Me-6-RNC[sub 9]H[sub 4]), 5a-c, R = H, Me, Cl, with compounds 5 being the major products. Compounds 2a-c, 4a-c, and 5a-c are new. Compounds 4a-c were also obtained from the reaction of 1a-c with HI. UV irradiation of 1b in the absence of iodine yielded the compounds Re[sub 2](CO)[sub 8][[mu]-2-S-3-CO[sub 2]Me-6-MeNC[sub 9]H[sub 4]] ([mu]-H) , 6b, Re[sub 2](CO)[sub 7][[mu]-2-S-3-CO[sub 2]Me-6-MeNC[sub 9]H[sub 4]]([mu]-H) , 7b, and 5b, while UV irradiation of 6b yielded 7b and 5b plus Re[sub 3](CO)[sub 12]([mu]-H)[sub 3]. UV irradiation of 2b in the presence of CO yielded 5b plus Re[sub 2](CO)[sub 8]([mu]-I)[sub 2]. UV irradiation of 3b also yielded 2b, 5b, and some 7b. Treatment of 7b with iodine yielded 2b. Finally, from the UV irradiation of 5b the dimer [Re(CO)[sub 3](2-S-3-CO[sub 2]Me-6-MeNC[sub 9]H[sub 4])][sub 2], 8b, was obtained in 57% yield. Complexes 2b, 4c, 5b, 6b, 7b, and 8b were characterized by single crystal X-ray diffraction analyses. The compounds 2 and 5-8 all contain substituted quinoline-2-thiolate ligands formed by the coupling of one of the carbon atoms of the aryl ring to the hydrogen-substituted carbon atom of the alkeny group. Crystal data are provided. 11 refs., 6 figs., 7 tabs.