Homogeneous catalytic hydrogenation. 6. Synthetic and mechanistic aspects of the regioselective reductions of model coal nitrogen, sulfur, and oxygen heteroaromatic compounds using the (.eta.5-pentamethylcyclopentadienyl)rhodium tris(acetonitrile) dication complex as the catalyst precursor

Abstract

The synthetic and mechanistic aspects of the regioselective hydrogenation of representative mono and polynuclear heteroaromatic nitrogen, sulfur, and oxygen model coal compounds such as 2-methylpyridine (1), N-methylindole (2), benzofuran (3), benzothiophene (4), quinoline (5), 2-methylquinoline (6), 5,6- and 7,8-benzoquinolines (7 and 8), and acridine (9) were studied with a (η 5 -pentamethylcuclopentadienyl)rhodium tris(acetonitrile) dicationic complex, [Cp*Rh(CH 3 CN) 3 ] 2+ , as the catalyst precursor. The order of relative rates as a function of structure was found to be 8>>>9>5>7>6>4>>1-3