Simple Methodology for Syntheses of Porphyrins Possessing Multiple Peripheral Substituents with an Element of Symmetry
摘要:
New methodology was developed for synthesis of regiochemically pure porphyrins with D-2h symmetry (e.g. 9) via tetramerization reactions involving two different pyrroles. The two pyrrole components were a 2,5-diunsubstituted pyrrole (e.g. 11) and a 2,5-bis[(N,N-dimethylamino)methyl]pyrrole (e.g, 10), the latter being formed from a 2,5-di-unsubstituted pyrrole by treatment with excess Eschenmoser's reagent (N,N-dimethylmethyleneammonium iodide). A bis-butanoporphyrin 16 was transformed into the corresponding opp-bis-benzoporphyrin 17 by treatment with DDQ. The synthetic method was further extended to allow the synthesis of more unsymmetrical porphyrins, with C-2v symmetry (e.g. 32), by reacting a tripyrrane (e.g. 27) with a 2,5-bis[(N,N-dimethylamino)methyl]pyrrole (e.g. 18). The structures and substituent arrays in both type of porphyrins were confirmed by single-crystal X-ray crystallography.
One-pot synthesis of regiochemically pure porphyrins from two different pyrroles
作者:Liem T. Nguyen、Mathias O. Senge、Kevin M. Smith
DOI:10.1016/s0040-4039(00)78348-1
日期:1994.10
of Eschenmoser's reagent (N,N-dimethylmethyleneammonium iodide) affords 2,5-bis-(N,N-dimethylaminomethy)pyrroles (e.g. 7); reaction with a second 2,5-di-unsubstituted pyrrole (e.g. 8) gives pure porphyrin (e.g. 9) with identical substituents on opposite pyrrole sub-units.
Coplanar conjugated β-nitroporphyrins and some aspects of nitration of porphyrins with N2O4
作者:Olivier Siri、Laurent Jaquinod、Kevin M Smith
DOI:10.1016/s0040-4039(00)00468-8
日期:2000.5
Sterically controlled N2O4 nitration of a meso-2,3-unsubstituted porphyrin or a bis-α-unsubstituted pyrroloporphyrin affords coplanar conjugated β-nitroporphyrins displaying strong electronic interactions.
内消旋-2,3-未取代的卟啉或双-α-未取代的吡咯卟啉的立体控制的N 2 O 4硝化作用提供了共面共轭的β-硝基卟啉,显示出很强的电子相互作用。
Porphyrins with exocyclic rings. Part 19: Efficient syntheses of phenanthrolinoporphyrins
作者:Timothy D. Lash、Yanning Lin、Bennett H. Novak、Mihir D. Parikh
DOI:10.1016/j.tet.2005.09.089
日期:2005.12
5-Nitro-1,10-phenanthrolines react with isocyanoacetate esters in the presence of DBU in THF to give excellent yields of the corresponding phenanthrolinopyrroles. These were condensed with acetoxymethylpyrroles using catalytic quantities Of p-tolenesulfonic acid in acetic acid to give dipyrrylmethanes, but these structures proved to be poorly suited for porphyrin synthesis due to the electron-withdrawing nature of the fused phenanthroline unit. However, phenanthrolinopyrrole ethyl esters could be converted to the corresponding alpha-unsubstituted pyrroles with KOH in ethylene glycol at 180-190 degrees C and these condensed with 2 equiv of acetoxymethylpyrroles in refluxing acetic acid-isopropyl alcohol to give tripyrranes. In a one pot procedure, tripyrrane di-tert-butyl esters were treated with TFA at room temperature to cleave the protective groups, diluted with dichloromethane, reacted with pyrrole dialdehydes and oxidized to afford phenanthrolinoporphyrins in 52-83% yield. These conditions also allow the synthesis of porphyrins with additional fused acenaphthylene or phenanthrene rings. Although the UV-vis spectra for these porphyrins are unexceptional, the presence of an external coordination site allows many potential applications to be considered. Porphyrins with two phenanthroline units could not be prepared by the '3 + 11 strategy. Instead, alpha-unsubstituted phenanthrolinopyrroles were reacted with a bis(dimethylaminomethyl)pyrrole in refluxing acetic acid to give moderate yields of the corresponding opp-diphenanthrolinoporphyrins. In one case, a triphenanthrolitioporphyrin and trace amounts of an adj-diphenanthrolinoporphyrin were formed as by-products. (c) 2005 Elsevier Ltd. All rights reserved.
Simple Methodology for Syntheses of Porphyrins Possessing Multiple Peripheral Substituents with an Element of Symmetry
作者:Liem T. Nguyen、Mathias O. Senge、Kevin M. Smith
DOI:10.1021/jo951870f
日期:1996.1.1
New methodology was developed for synthesis of regiochemically pure porphyrins with D-2h symmetry (e.g. 9) via tetramerization reactions involving two different pyrroles. The two pyrrole components were a 2,5-diunsubstituted pyrrole (e.g. 11) and a 2,5-bis[(N,N-dimethylamino)methyl]pyrrole (e.g, 10), the latter being formed from a 2,5-di-unsubstituted pyrrole by treatment with excess Eschenmoser's reagent (N,N-dimethylmethyleneammonium iodide). A bis-butanoporphyrin 16 was transformed into the corresponding opp-bis-benzoporphyrin 17 by treatment with DDQ. The synthetic method was further extended to allow the synthesis of more unsymmetrical porphyrins, with C-2v symmetry (e.g. 32), by reacting a tripyrrane (e.g. 27) with a 2,5-bis[(N,N-dimethylamino)methyl]pyrrole (e.g. 18). The structures and substituent arrays in both type of porphyrins were confirmed by single-crystal X-ray crystallography.