Synthesis of porphin analogues containing furan and/or thiophen rings

Abstract

The preparation of 21-oxa, 21-thia-, 21,23-dioxa-, 21,23-dithia-, and 21-oxa-23-thia-porphins is described. These new porphin analogues have spectral properties similar to those of the porphins, which supports their formulation as aromtic macrocycles. Surprising basicity is displayed by 21,22- and 21,23-dioxaporphins and unusual mass spectra are produced by the oxaporphins. Only the 21-oxa- and 21-thia-porphins form metal complexes under the usual conditions used for metalloporphin formation. The results of deuterium exchange studies on the new macrocycles are reported.