Steroids metalloporphyrin

Moreover, products like alcohols will coordinate to the metal. Accordingly, product release may be rate determining for these membrane spanning steroidal metalloporphyrins. 

Groves JT, Neumann R (1989) Regioselective oxidation catalysis in synthetic phospholipid-vesicles - membrane-spanning steroidal metalloporphyrins. J A Chem Soc 111 2900-2909... 

Cytochrome P-450 can perform both intramolecular and intermolecular nitrene insertions with 106 in water solution [181]. However, the intermediate metallo-nitrene (108) also hydrolyzed to some extent so the enzyme performed a hydroxylation as well as an amidation. Although we have also performed an intermolecular amidation of a steroid, using such a metalloporphyrin reaction with 106 to form 112 [182], we have not yet extended it to the kinds of directed functionalizations described above with either benzophenones or chlorinations. 

The most important by-product of the analytic and synthetic work accomplished so far is knowledge about the stereochemistry and reactivity of natural compounds. There is an enormous potential for the chemists of the twenty-first century lying in the mastery and application of this knowledge in order to produce organized and finally functional materials. Typical contemporary examples include surface monolayers on metals and colloids made of fatty acid and steroid derivatives, the regio- and stereoselective assembly reactions between steroids and carbohydrates, coupled redox chains of metalloporphyrins and vitamins, noncovalent fibers made of amino acids, nucleotides, and saccharides, and the functionalization of proteins by incorporation of reactive molecules. The field of supramolecular or noncovalent natural compound chemistry has been scientifically fruitful for several decades and is presently exploited for the development of useful molecular devices and machines as well as for medical applications. 

Iodosylbenzene has been used as an effective oxidant in hydrocarbon hydroxylation catalyzed by metal-loporphyrins [687-696]. In particular, various iron(III) and manganese(in) porphyrins can be used as catalysts in hydroxylations of cyclohexane, cyclohexene, adamantane and aromatic hydrocarbons [687,688, 692]. Breslow and coworkers have reported regioselective hydroxylations of several steroidal derivatives catalyzed by metalloporphyrins [689-691]. In a specific example androstanediol derivative 644 was... 

IV-Tosyliminoiodanes, ArINTs, have found synthetic application as useful nitrene precursors in transition metal catalyzed amidation of saturated C—H bonds in various organic substrates. Breslow and coworkers have developed the regioselective amidation of steroidal derivatives catalyzed by metalloporphyrins [690,691]. Specifically, the aromatic steroid equilenin acetate 657 undergoes regioselective and stereoselective amidation catalyzed by a manganese porphyrin using PhINTs as the nitrene donor (Scheme 3.261) [690],... 

We produced metalloporphyrins 30 carrying iron or manganese atoms and with four cyclodextrins linked to the porphyrins, and saw that they could catalyticaUy direct oxidation of hydrophobicaUy doubly boimd substrates. Then we showed that the system would hydroxylate a bound steroid 31 with complete selectivity for the C-6 equatorial hydrogen, producing the 6-q -hydroxy steroid 32 (Fig. 1.18). ° By adding some fluorine atoms to this system in catalyst 33 to stabilize the catalyst against self-oxidation, we greatly improved the catalytic turnovers. 

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