FACILE ELABORATION OF PORPHYRINS VIA METAL-MEDIATED CROSS-COUPLING

Metal-mediated cross-coupling methodologies have been successfully employed to porphyrinic systems, providing a powerful, versatile, and general synthetic approach for the fabrication of elaborated porphyrin structures. A large number of coupling reactions have been carried out at two halogenated porphyrin templates, [2-bromo-5,10,15,20-tetraphenylporphinato]zinc and [5,15-dibromo-10,20-diphenylporphinato]zinc, generating a variety of porphyrins, 10 of which are novel: [2-n-butyl-5,-10,15,20-tetraphenylporphinato]zinc(II), [2-(2,5-dimethoxyphenyl)-5,10,15,20-tetraphenylporphinato]-zinc(II), [2-(9-anthracenyl)-5,10,15,20-tetraphenylporphinato]zinc(II), [2-vinyl-5,10,15,20-tetraphenylporphinato]zinc(II), [2,5,10,15,20-pentaphenylporphinato]zinc(II), [2-isobutyl-5,10,15,20-tetraphenylporphinato]zinc(II), [2-(pentafluorophenyl)-5,10,15,20-tetraphenylporphinato]zinc(II), [5,15-bis[[2-(4'-methyl-2'-pyridyl)-4-pyridyl]methyl]-10,20-diphenylporphinato]zinc(II), [5,15-dimethyl-10,20-diphenylporphinato]zinc(II), [5,15-divinyl-10,20-diphenylporphinato]zinc(II), [5,15-bis(2,5-dimethoxy-phenyl)-10,20-diphenylporphinato]zinc(II), and [5,15-bis(pentafluorophenyl)-10,20-diphenylpor-phinato]zinc(II). The structures of [2,5,10,15,20-pentaphenylporphinato]zinc(II) and 5,15-bis(pentafluorophenyl)-10,20-diphenylporphyrin have been determined; X-ray data areas follows: P2(1)/n with a = 21.425(4) angstrom, b = 9.718(1) angstrom, c = 24.905(2) angstrom, beta = 110.83(1)-degrees, V = 4846(3) angstrom3, d(calc) = 1.260 g cm-3, and Z = 4 for the former; and P2(1)/c with a = 15.223(2) angstrom, b = 10.162(1) angstrom, c = 12.375(2) angstrom, beta = 112.75(2)-degrees, V = 1765.6(9)angstrom3, d(calc) = 1.495 g cm-3, and Z = 2 for the latter. This study demonstrates that cross-coupling reactions at the porphyrin periphery are seemingly not subject to the steric or electronic constraints that often limit the scope of these reactions in simple aryl and vinyl systems.