Oxidative cyclization of a,c-biladienes: The role of the metal ion
Previous literature work has assumed that the metal ion in metal-assisted a,c-biladiene cyclizations serves as a chelator as well as an oxidant. New results suggest that the metal is not of primary importance in aligning the tetrapyrroles into the proper cyclic conformation prior to cyclization. Though the metal insertion into the tetrapyrrole can take place at any stage in the reaction sequence, it appears only to be essential after formation of the 1,20-dihydroporphyrin intermediate, wherein it serves to facilitate the elimination of the 1-substituent to produce porphyrin. © 1998 John Wiley & Sons, Ltd.
Publication Source (Journal or Book title)
Journal of Porphyrins and Phthalocyanines
Lin, J., Holmes, R., & Smith, K. (1998). Oxidative cyclization of a,c-biladienes: The role of the metal ion. Journal of Porphyrins and Phthalocyanines, 2 (4-5), 363-368. https://doi.org/10.1002/(sici)1099-1409(199807/10)2:4/5<363::aid-jpp91>3.0.co;2-c