Polyhaloporphyrins:  Unusual Ligands for Metals and Metal-Catalyzed Oxidations

Abstract

3) This paper as originally submitted to the Editor cited more than 100 references, which occupied fully one-third of the paper. In order to meet the space criteria of Accounts, we have chosen, where possible, to cite only recent references. A recent monograph gives an excellent up-to-date review of many areas touched upon here. Cytochrome P-450: Structure, Mechanism and Biochemistry, 2nd ed.; Ortiz de Montellano, P. R., Ed.; Plenum Press: New York, 1995. (4) Even the trivial names of porphyrins are frequently complex. In this review the major porphyrins are abbreviated as follows: TPP ) mesotetraphenylporphyrin (2a) etc. as shown for structures 2-14.Teddy G. Traylor (1925Traylor ( -1993 never graduated from high school, but after the war, where he served in the Merchant Marine, he received his Ph.D. at UCLA with Saul Winstein and then was a postdoctoral fellow with Paul Bartlett at Harvard. He was the first organic chemist hired at UCSD, where he was a pioneer in organometallic chemistry. Teddy was the first to publish papers on superstructured porphyrins, and his research on oxygen binding and P-450 chemistry was seminal for the past two decades. His love of chemistry was surpassed only by his love of life. We are sorry that he is not with us to still enjoy them. David Dolphin was born in London, England, at the beginning of the Second World War. After obtaining his undergraduate and graduate degrees at the University of Nottingham, he was a postdoctoral fellow with R. B. Woodward at Harvard and then joined the faculty there in 1966. In 1973 he joined the University of British Columbia, where he has been acting Dean of Science and is the NSERC/ QLT Industrial Research Professor in Photodynamic Technology. He is also the V.P. of Technology Development at QLT PhotoTherapeutics, a Vancouver-based biotechnology company that is the world leader in photodynamic therapy. Lily Y. Xie was born in Chongqing, People's Republic of China. She received her B.Sc. degree at Peking University in 1983 and her Ph.D. in 1990 at the University of British Columbia (UBC) under the direction of Brian R. James. She worked as a postdoctoral fellow with David Dolphin at UBC and then with Alison Butler at the

Catalytic activity in oxidation reactions of anionic iron(III) porphyrins immobilized on raw and grafted chrysotile

“…The possibility of the molecular interaction of the Fe(TDFSPP) species in solution could be another reason for the low catalytic activity observed in the homogeneous catalysis because it can be accompanied by μ-oxo complex formation. 17,[37][38][39] The oxidative degradation of the catalyst in solution is frequently responsible for the low yield in catalytic reactions using metalloporphyrins 17 but not for second generation iron porphyrins and in cases with a low FePor/oxidant molar ratio such as was used in run 1 (1:50).…”

“…[1][2][3][4] This class of compounds is used in solution or following immobilization in organic amorphous polymers and crystalline inorganic materials such as silica, [5][6][7] zeolites, 8,9 clay from the smectite group (montmorillonite) 10,11 and others. [12][13][14][15][16] The use of metalloporphyrins substituted with electron-withdrawing groups (the so-called second generation porphyrins 17 ) and their immobilization, has resulted in efficient and selective catalysts for oxidation reactions, since the support can impose shape selectivity and promote a special environment, favoring the approach of the substrate to the active catalytic specie. [5][6][7]12,13,18 In addition, the immobilization may prevent molecular aggregation or bimolecular self-destruction reactions, which can lead to deactivation of catalytically active metalloporphyrin species.…”

Preparation of Polymeric Solids based on Porphyrins and Preliminary Investigation of the Catalytic Activity in Cyclooctene Oxidation

“…[1][2][3][4][5][6] A porfirina P apresentou banda Soret em 442 nm e o sólido SP em 447, valores deslocados para maiores comprimentos de onda em relação a banda Soret observada para essa porfirina em solução ( a cerca de 420 nm). Tal deslocamento pode estar associado à protonação dos nitrogênios pirrólicos do anel macrocíclico ou ainda a distorções do anel ocorridas, por exemplo, devido às novas ligações formadas no processo de polimerização semelhante aos solidos obtidos pela imobilização de metaloporfirinas em suportes inertes.…”

“…O sólido SMP1 apresentou atividade catalítica similar à apresentada pela metaloporfirina MP em solução (catálise homogênea) na oxidação do cis-cicloocteno, sendo facilmente recuperado e reutilizado em outro ciclo catalítico. 2,3 A estratégia sintética na preparação de metaloporfirinas tem levado a uma melhora significativa na atividade catalítica desses compostos em reações de oxidação em fase homogênea. 3,4 Porém, a pesquisa por catalisadores ainda mais eficientes, seletivos e reutilizáveis, levou ao desenvolvimento de compostos que pudessem atuar na catálise heterogênea.…”

Oxidative Activation and Degradation of Organophosphorus Pesticides Mediated by Iron Porphyrins

“…3,6,7) The various types of electrondeficient iron porphyrins have been recently synthesized to increase oxidative reactivity and moreover, the introduction of bulky phenyl groups at meso-positions of the porphyrin ring has successfully hindered the unfavorable formation of the moxo dimer in the catalytic oxidation. 8) The co-existence of an oxidant such as hydrogen peroxide in organic solvent was found to well simulate the P450-catalyzed reactions of many chemicals including several carbamate insecticides. 3,9) The oxidative desulfuration of phosphorothioate pesticides to form the corresponding oxon or S-oxidation of the alkylthio group to sulfoxide and sulfone is a well-known metabolic reaction catalyzed by P450.…”