Facile synthesis of meso-substituted dipyrromethanes and porphyrins using cation exchange resins

Synthesis of Highly Substituted Nitro/Ha­lo-meso-tetraaryl­porphyrins by Tandem Cyclocondensation/Aromatic Electrophilic Nitration Reactions

“…In this work, we used for this purpose (as substrates) readily available halo-substituted m-TPP derivatives. [7][8][9] All these compounds (substrates and products) are also involved in another our ongoing project. They are very good models for calculations the 1 H NMR substituent increments in meso-tetraarylporphyrin systems.…”

“…They have already been described in the previous literature: (1a-c, [8] 7 [7,9] Nitration of 5,10,15,20-tetrakis(3-fluorophenyl)porphyrin (1a). 5,10,15,20-Tetrakis(3-fluorophenyl)porphyrin (1a; 80 mg, 0.12 mmol) was dissolved in CHCl 3 (24 ml), and the solution was stirred under argon and cooled to 0-5˚C.…”

Synthesis of dipyrromethanes in aqueous media using boric acid

“…[16][17][18] Our research group has developed a few green methods for synthesis of dipyrromethanes and related compounds [19][20][21][22] in addition to other groups. [23][24][25] Boric acid has been used as catalyst for synthesis of bis(indolyl)methanes, 26 benzoxanthenes, 27 dehydration of glucose, 28 protection and deprotection of alcohols and ethers, 29 Nacylation, 30 bromination, 31 aza Michael reactions, 32 Biginelli reactions 33 and other condensation reactions. [34][35][36] Herein, we have described the use of boric acid as an innocuous and highly efficient catalyst for the condensation reaction of pyrrole and aldehydes in aqueous medium to afford the corresponding dipyrromethanes.…”

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

“…In recent years Amberlyst™-15 has been explored as a powerful catalyst for various organic transformations [38]. The reaction of pyrrole with different aldehydes in dichloromethane in the presence of Amberlyst TM -15 gave dipyrromethanes, which in the presence of excess aldehydes followed by oxidation with chloronil [39] or DDQ [40] gave 5,10,15,20-tetraaryl porphyrins, whereas the reaction of pyrrole with aldehydes in the absence of solvent followed by oxidation with DDQ gave 5,10,15-triarylcorroles [40]. Herein we report an eco-friendly synthesis of calix [4]pyrroles and related products under mild reaction conditions by the reaction between ketones and pyrrole catalyzed by Amberlyst™-15.…”