First synthesis of meso-substituted pyrrolo[1,2-a]quinoxalinoporphyrins

Abstract

SummaryA synthetic protocol for the construction of new meso-substituted pyrrolo[1,2-a]quinoxalinoporphyrins is described starting from 5-(4-amino-3-nitrophenyl)-10,15,20-triphenylporphyrin. The reaction of this porphyrin with 2,5-dimethoxytetrahydrofuran, followed by the reduction of the nitro group in the presence of NiCl2/NaBH4 afforded 5-(3-amino-4-(pyrrol-1-yl)phenyl)-10,15,20-triphenylporphyrin. This triphenylporphyrin underwent a Pictet–Spengler cyclization after the reaction with various aromatic aldehydes followed by in situ KMnO4 oxidation to form target porphyrin analogues in good yields. The structures of all synthesized products were established on the basis of spectral data and elemental analyses.

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

“…Continuing our work on the functionalization of porphyrin at the meso -position [ 32 – 33 ], we used the CuAAC click protocol to synthesize meso -phenyltriazole-linked porphyrin-coumarin dyads 44–48 in good to excellent yields. Firstly, Zn(II) meso -phenyltriazole-linked porphyrin-coumarin conjugates 44a–48a were synthesized by using the “click reaction” between zinc(II) 5-(4-azidophenyl)-10,15,20-triphenylporphyrin ( 39a ) and diverse alkyne-substituted coumarins 6–10 in DMF containing CuSO 4 ·5H 2 O and ascorbic acid at 80 °C [ 34 ] ( Scheme 8 ).…”

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

“…Among these, the Clauson–Kaas pyrrole synthesis has received much attention because the synthesized pyrrole contains unsubstituted carbons that can be used for further functionalization. This methodology has been applied to diverse areas of chemistry, including natural product synthesis [ 45 – 46 ], medicinal chemistry [ 47 – 48 ], polymer chemistry [ 49 – 50 ] and porphyrin chemistry [ 51 – 53 ].…”

PIFA-promoted intramolecular oxidative cyclization of pyrrolo- and indolo[1,2-a]quinoxalino-appended porphyrins: an efficient synthesis of meso,β-pyrrolo- and indolo[1,2-a]quinoxalino-fused porphyrins

“…With interesting biological profiles and usefulness as fluorescent materials, various meso /β-substituted pyrrolo[1,2- a ]quinoxalino porphyrins 1–2 were reported with weak perturbation in absorption spectra and modest change in band intensity of emission spectra. 16,17…”

“…[13][14][15] With interesting biological profiles and usefulness as fluorescent materials, various meso/β-substituted pyrrolo[1,2-a]quinoxalino porphyrins 1-2 were reported with weak perturbation in absorption spectra and modest change in band intensity of emission spectra. 16,17 In efforts to prepare diverse porphyrinoids, Nath and coworkers reported interesting π-extended β,β′-fused β-pyrrolo [1,2-a]quinoxalinoporphyrins 3 involving Pictet-Spengler reaction of 2-amino-3-(pyrrol-1-yl)-5,10,15,20-tetraphenyl-porphyrins with different aldehydes. 18 With notable red-shifted Soret band and more intense Q band, the β,β′-quinoxalino-fused porphyrins 3 were found to be useful in the selective detection of mercury ion.…”