Membrane-bound cytochrome P-450 mimic. Polymerized vesicles as microreactors.

Supplementary Material Available: Preparative methods for the starting materials, stereochemical assignments of 1,3-diols listed in Table I, and 400-M Hz 'H N M R spectra of acetonides of 1-3 and 7 (6 pages). Ordering information is given on any current masthead page. The Cytochrome P-450 dependent monooxygenases are mem­ brane-bound enzymes that catalyze a great variety of reactions, among which is the epoxidation of alkenes by molecular oxygen.1 The active center of the enzymes contains an iron(III) proto­ porphyrin IX and axial thiolate ligand. After being reduced to iron(II) this center binds and cleaves molecular oxygen, whereupon water and a high-valent iron-oxo complex are formed. The latter species transfers its oxygen to a substrate molecule.1,2 The electrons required in the process are provided by N A D PH via a coupled electron transferring enzyme system.1 We describe here a synthetic model system of cytochrome P-450 which incorporates all the features of the natural enzyme system, i.e., (i) a mem-braneously bound metalloporphyrin (complex 1), (ii) an axial ligand (A^-methylimidazole), (iii) an electron donor (colloidal P t-H 2),2a (iv) an electron carrier (methylene blue), and (v) a membrane system (polymerized vesicles of 2) which holds com­ ponents within its bilayer or within its inner aqueous compartment (Figure 1).