A New Iodovinyl Derivative of Methyl Pyropheophorbide d Obtained via Takai Olefination Reaction

Modification of chlorin derivatives, which leads to extension of the conjugation chain along the y axis, is the most important direction in the field of natural tetrapyrrole compounds. Iodine-containing derivatives of porphyrins are valuable reagents in such Pd-catalyzed reactions as Suzuki, Mizoroki-Heck, Stille, and Sonogashira couplings, as well as Buchwald-Hartwig amination. A new alternative way for functionalization of C32-position of formyl group of methyl pyropheophorbide d by introducing ofiodine has been developed. We have proposed an one-step synthesis of methyl 3-(2-iodovinyl)pyropheophorbide d, including Takai reaction between methyl pyropheophorbide d, i o d ofo rm and CrCl2. This functionalized derivative can be useful for further synthesis of derivatives with pi-extending system by Pd-catalyzed cross-coupling reaction.