A series of manganese and iron porphyrins with sterically protected pockets are shown to be shape selective alkane hydroxylation catalysts. With iodosobenzene as oxidant, good regioselectivity is observed for hydroxylation of alkanes at the least hindered methyl group by using the very sterically hindered (5,10,15,20-tetrakis(2’,4’,6’-triphenylphenyl)porphyrinato)manganese(III) acetate (MnTTPPP...