Electrophilic mercuration reactions of derivatives of deuteroporphyrin IX: new syntheses of coproporphyrin III, harderoporphyrin, isoharderoporphyrin, and S-411 porphyrin (dehydrocoproporphyrin)

Abstract

Treatment of copper(II) deuteroporphyrin IX dimethyl ester (17) with mercuric acetate affords a peripherally metalated species in which the 2- and 4-positions are mercurated. Acidic deuterolysis and sodium borodeuteride reduction suggest that some mercury also becomes attached to the α and β meso positions. Treatment of the dimercurated material with methyl acrylate and LiPdCl3 gives the corresponding diacrylate, 8, which can be hydrogenated to afford coproporphyrin III tetramethyl ester (7). Mercuration of copper(II) monoacetyldeuteroporphyrins IX 15 and 16 can also be readily accomplished, and in this way a new synthetic route to harderoporphyrin and isoharderoporphyrin trimethyl esters (14 and 24, respectively) is developed. A novel method for deacetylation of copper(II) porphyrins is described, and along with the mercuration/olefin coupling reaction, this is employed in a new synthesis of the S-411 porphyrin (dehydrocoproporphyrin) obtained from meconium, as its tetramethyl ester, 34. © 1983, American Chemical Society. All rights reserved.