Accelerated Bergman cyclization of porphyrinic-enediynes.
The Bergman cyclization of simple diethynylporphyrinic-enediynes exhibits a double activation barrier to the formation of Bergman cyclized product. Addition of H-atom acceptor accelerates the formation of the picenoporphyrin, indicating that the second barrier is rate limiting.
Department of Chemistry, Indiana University, Bloomington, IN, USA.
Mahendra
M
Nath
John C
JC
Huffman
Jeffrey M
JM
Zaleski