Synthesis, properties and reactivity of an <i>ortho</i>-phenylene-cyclopentene-bridged tetrapyrrole

Increasing the number of meso-methine carbons porphyrin has led to a creation series vinylogous expanded porphyrins, while introduction an ortho-phenylene-unit as pyrrole-connecting two-carbon bridge usually leads prevention effective macrocyclic conjugation. Cyclopentene can serve conjugative increase conjugation owing its cis-geometry. In this work, ortho-phenylene-cyclopentene-bridged tetrapyrrole 5 was prepared on basis coupling strategy. The exhibited slightly more features compared ortho-phenylene-bridged 4. Oxidation with [bis(trifluoroacetoxy)iodo]benzene (PIFA) at low temperature afforded partly fused tetrapyrrolic compound 9 having spiro-connected pyrrolo[2,1-[Formula: see text]]isoindole moiety.