Synthesis and atropisomerism of meso-tetraarylporphyrins with mixed meso-aryl groups having ortho-substituents
摘要:
meso-Tetraarylporphyrins having two kinds of ortho-substituted meso-aryl groups alternately at 5-, 10-, 15-, and 20-positions have been prepared by way of the modified MacDonald [2+2]-type condensation of alpha-alpha'-free aryldipyrrylmethanes with aryl aldehydes. 5,15-Di(2-acetylaminophenyl)-10,20-di-1-(2-methoxynaphthyl)porphyrin was prepared by way of two different combinations of aryldipyrrylmethanes and aryl aldehydes. The five atropisomers (alpha alpha'beta beta', alpha alpha'beta alpha', alpha beta'alpha beta', alpha alpha'alpha beta' alpha alpha'alpha alpha') expected for these porphyrins were separated and characterized on the basis of the H-1 NMR spectra and thermal isomerization behavior. (C) 1998 Elsevier Science Ltd. All rights reserved.