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Titolo:
REACTION OF METALLO-2-NITRO-5,10,15,20-TETRAPHENYLPORPHYRINS WITH OXYANIONS - TEMPERATURE-DEPENDENT COMPETITION BETWEEN NUCLEOPHILIC-ADDITION AND SINGLE-ELECTRON TRANSFER PROCESSES
Autore:
CROSSLEY MJ; KING LG;
Indirizzi:
UNIV SYDNEY,SCH CHEM SYDNEY NSW 2006 AUSTRALIA
Titolo Testata:
Journal of the Chemical Society. Perkin transactions. I
fascicolo: 11, , anno: 1996,
pagine: 1251 - 1260
SICI:
0300-922X(1996):11<1251:ROMWO>2.0.ZU;2-C
Fonte:
ISI
Lingua:
ENG
Soggetto:
BETA-PYRROLIC POSITION; PORPHYRIN SYSTEMS; 2-SUBSTITUTED 5,10,15,20-TETRAPHENYLPORPHYRINS; EFFICIENT SYNTHESIS; TAUTOMERISM; ION; METALLOPORPHYRINS; SUBSTITUTION; SPECTROSCOPY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
50
Recensione:
Indirizzi per estratti:
Citazione:
M.J. Crossley e L.G. King, "REACTION OF METALLO-2-NITRO-5,10,15,20-TETRAPHENYLPORPHYRINS WITH OXYANIONS - TEMPERATURE-DEPENDENT COMPETITION BETWEEN NUCLEOPHILIC-ADDITION AND SINGLE-ELECTRON TRANSFER PROCESSES", Journal of the Chemical Society. Perkin transactions. I, (11), 1996, pp. 1251-1260

Abstract

The outcome of the reaction of metallo-2-nitro-5,10,15,20-tetraphenylporphyrins with oxyanions is dependent both on the nature of the coordinated metal ion and on the reaction temperature. Metallo-2-nitro-5,10,15,20-tetraphenylporphyrins with relatively electronegative chelated metal ions (Cu-II,Ni-II and (FeCl)-Cl-III) react with methoxideion in N,N-dimethylformamide to afford mainly the corresponding metallated 2-methoxy-3-nitroporphyrins and 2,2-dimethoxy-3-nitro-2,3-dihydroporphyrins. The zinc(II) chelate 7 is unreactive towards methoxide under identical conditions. When the room temperature reaction of itro-5,10,15,20-tetraphenylporphyrinato)nickel(II) 5 with methoxide is quenched withwater after 1 min, the methoxy-3-nitro-2,3-dihydroporphyrinato)nickel(II) 14 is obtained. Inclusion of nitrobenzene in the reaction of the copper(II) chelate 4 with methoxide is beneficial and results in the formation of the 2,2-dimethoxy-3-nitro-2,3-dihydroporphyrin 8 in 90% yield. Reaction of 4 with benzyl oxide ion gives analogous products but in lower yield, while the major product from reaction of 4 with hydroxide ion is the 2-hydroxy-3-nitroporphyrin 16. At elevated temperaturesthe nature of the reaction of the copper(II) chelate 4 with methoxidechanged to afford the corresponding copper(II) 2-alkoxyporphyrin 10 and the denitrated parent porphyrin 20; the later compounds-arise from radical reactions. A mechanistic rationale for the processes involved in these temperature-dependent reactions is presented. The ease with which these reactions occur is a consequence of the fact that all the reaction intermediates are able to retain macrocyclic aromaticity.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 18/09/20 alle ore 19:34:41