A survey of acid catalysts for use in two-step, one-flask syntheses of meso-substituted porphyrinic macrocycles

[GRAPHICS] Diverse Lewis acids and Bronsted acids were examined in the two-step, one-f lask synthesis of meso-tetraphenylporphyrin, N-confused tetraphenylporphyri n, and tetraphenylsapphyrin. The scope of acid catalysis was found to be ve ry broad, with 35 of 45 acids providing TPP in yields ranging from 5% to 58 %, NC-TPP was also widely observed in yields of 1-40%, and TPS was infreque ntly observed in yields of <1%. Additionally, conditions were found for dir ect preparation of magnesium TPP and copper TPP.