P mimics

Cyclodextrins have also been used as cytochrome P-450 mimics, in which the cyclodextrin cavity is linked covalently to an iron porphyrinato core, as in 12.32. Binding of hydrophobic substrates, such as... 

Scheme 12.16 Cytochrome P-450-mimic microreactor based on a Pt filled vesicle. (MBox/red = methylene blue electron carrier, oxidised and reduced forms, respectively.)...

Our principal target in P-450 mimics was the selective oxidation of saturated carbons directed by geometric control, not by intrinsic reactivity. In our first study, we examined selective geometrically controlled attack on aliphatic C-H bonds by photo-excited benzophenones [145]. In a process we labeled remote oxidation", photolysis of a long-chain ester 69 of benzophenone-4-carboxylic acid afforded insertion into CH2 groups far into the chain. 

Figure 33 Composite catalytic membrane as heterogeneous cytochrome P-450 mimic, matrix polydimethylsiloxane (PDMS), filler FePc-loaded zeolite Y (30 wt%) [91]...

Isocyanides bearing ammonium side-chains 51 and 52 have been polymerized in the presence of nickel catalysts [72, 73]. The amphiphilic isocyanide 51 forms vesicles on dispersion in water. The isocyano groups located in the vesicle bilayers were polymerized by nickel capronate to form polymerized vesicles. The isocyanide 51 was also used in the preparation of polymerized vesicles containing metalloporphyrin components within the bilayer membrane [74]. The redox behavior of this membrane-bound cytochrome P-450 mimic has been investigated in detail. In addition to those bearing cationic side chains, isocyanides 53 and 54 bearing zwitterionic side chains were successfully used [75]. 

R. Breslow, J. Yan, S. Belvedere, Catalytic hydroxylation of steroids by cytochrome P-450 mimics. Hydroxylation at C-9 with novel catalysts and steroid substrates, Tetrahedron Lett., 2002, 43, 363-365. 

Fig. 3 A cytochrome P-450 mimic for selective hydroxyiation of steroids. (From Ref. [16].)...

P-450 mimics to transfer nitrogen atoms, not just oxygen.Expansion of this approach to enzyme mimicry is still underway. 

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