Regioselective pyridination of m-benziporphyrin.
[reaction: see text] Reaction of tetraaryl-m-benziporphyrin with pyridine and silver tetrafluoroborate yields 22-pyridiniumyl-m-benziporphyrin as the only substitution product. This compound is further rearranged to a fused m-benziphlorin containing a 4a-azafluorene fragment. A mechanism involving a high-valent silver complex is proposed for the pyridination reaction.
Stepień
Marcin
M
Department of Chemistry, University of Wrocław, 14 F. Joliot-Curie St., Wrocław 50 383, Poland.
Latos-Grazyński
Lechosław
L