Synthesis of calixpyrroles and porphyrins over molecular sieve catalysts

Syntheses of Calix[4]Pyrroles by Amberlyst-15 Catalyzed Cyclocondensations of Pyrrole with Selected Ketones

“…These acids are considered hazardous and corrosive and their removal from the reaction mixtures is difficult. Recently, condensations in dichloromethane of pyrrole with dialkyl ketones in the presence of the molecular sieve Al-MCM-41 and the zeolite HY afforded dipyrromethane, calix [4]pyrroles and other linear products, but not the N-confused calix [4]pyrroles [36,37]. Amberlyst™-15 is an inexpensive and non-hazardous solid acid, useful as a catalyst.…”

Main Strategies for the Synthesis of meso-Arylporphyrins

“…The solvent-free methodology for the preparation of tetrapyrrole macroheterocycles was developed using zeolite catalysts [ 194 ]. The use of acid zeolite catalysts such as HZSM-5 and Al-MCM-41 in combination with microwave heating provided good yields and selec­tivity in the synthesis of tetraphenylporphyrin, tetra­kis(4-methoxyphenyl)porphyrin, tetrakis(4-methyl­phenyl)porphyrin, and calixarene.…”

Synthesis of N-heterocyclic compounds over zeolite molecular sieve catalysts: an approach towards green chemistry

“…The reason for long reaction time could also be due to the same factors as observed in cyclic ketones of higher ring size. Radha Kishan et al 104 also reported the synthesis of calix [4]pyrroles and porphyrins over zeolites under microwave irradiation.…”