New Syntheses and Reactions of Some Halogenated Porphyrins

Article abstract of DOI:10.1021/jo00284a033

Efficient syntheses of 2,4-dibromo- and 2,4-diiododeuteroporphyrin IX have been carried out by treating zinc(II) 2,4-bis(chloromercurio)deuteroporphyrin IX dimethyl ester (2) with bromine or iodine.Unavoidable mesochlorination occurs when 2 is treated with chlorine and with other free-radical chlorinating agents.Regioselective meso-chlorination and peripheral (β) bromination are shown to occur from brief treatment of copper(II) deuteroperphyrin IX or β-unsubstituted a,c-biladienes with the corresponding copper(II) halide in refluxing dimethylformamide.Protoporphyrin IX has been synthesized by vinylation of 2 via ethylene/LiPdCl3 (35percent yield), with vinyl bromide and Wilkinson's catalyst (63percent), or from 2,4-dibromodeuteroporphyrin IX with ethenyltributylstannane/(Ph3P)4Pd⁰ (85percent).