Biomimetic oxidation of unactivated carbons in steroids by a model of cytochrome P-450, oxorutheniumporphyrinate complex

Biomimetic oxidation of unactivated carbons for structurally different steroids was studied with a model of cytochrome P-450, oxorutheniumporphyrinate complex, which is generated in situ by 2,6-dichloropyridine N-oxide as an oxygen donor and (5,10,1 5,20-tetramesitylporphyrinate) ruthenium(II) carbonyl complex and HBr as catalysts. The O-insertion positions depended significantly on specific structural features of the substrates to give novel and remote-oxygenated steroids in one step. The electrophilic oxorutheniumporphyrinate attacked predominantly allylic and benzylic beta-carbons adjacent to a pi-bond and/or less hindered, electron-rich tert-methine carbons in the substrates to give regio- and stereoselectively the corresponding oxo and/or hydroxy derivatives.