A new synthetic approach to porphyrin-alpha-diones and a-2,3,12,13-tetraone: building blocks for laterally conjugated porphyrin arrays

We report the first use of the Dess-Martin periodinane (DMP) for the oxidat ion of an arylamine to an alpha -dione. The methodology is illustrated by t he preparation of free-base and metal chelated porphyrin-alpha -diones in u p to 52% yield by oxidation of 2-aminoporphyrins with the DMP. We also foun d that DMP could be used to oxidise a 2,3-diaminoporphyrin to a porphyrin-a lpha -dione in good yield with other free-base diaminoporphyrin isomers for ming a trans-porphyrintetraone in 20% yield.