Innate selectivity Carbon–hydrogen bond activation

for oxaziridine (left), 1st site oxidized preferably due not distance electron-withdrawing obz group because of substitution—the carbon tertiary—and more electron rich. similarly, secondary methylene position in trifluoromethyldioxirane (tfdo, right) farthest away electron-withdrawing group selectively oxidized. note here, oxaziridine, substitution @ carbon affects selectivity; secondary methylene position preferred on terminal methylene position because former has secondary carbon while latter has primary one.

in oxidation of cyclohexane compound, tertiary site on ring preferential on tertiary site of isopropyl substituent. 2 methyl groups hinder oxidation on isopropyl group, making less hindered cyclohexyl site more favorable.