Synthesis of vinylated 5,10,15,20-tetraphenylporphyrins via Heck-type coupling reaction and their photophysical properties

Abstract

The direct coupling reaction between substituted olefins and 5,10,15,20-tetrakis(4-bromophenyl)porphyrin, via a Heck-type reaction, constitutes a versatile method for the vinylation of 5,10,15,20-tetrakis(4-bromophenyl)porphyrin to yield new vinylated tetraphenylporphyrins quantitatively. Another strategy for the vinylporphyrin synthesis has been developed. A phosphapalladacycle has been used as catalyst for the coupling reaction between 4-bromoaryl aldehydes and olefins to yield vinyl aldehydes quantitatively. These aldehydes have been condensed with pyrrole, by the one-step nitrobenzene method, to give the corresponding vinylated tetraphenylporphyrins. Photophysical studies of these new porphyrins are also reported.