Extension of antiaromatic norcorrole by cycloaddition

Chem Commun (Camb). 2018 Mar 6;54(20):2510-2513. doi: 10.1039/c8cc00447a.

Abstract

The antiaromatic ring of norcorrole, a contracted tetrapyrrolic porphyrinoid, was subjected to [2+3] dipolar cycloaddition of iminonitriles. The paratropic character of the resulting chiral chlorins was retained. The chlorins were easily dehydrogenated in the presence of air, yielding pyrazole-fused norcorroles with markedly enhanced paratropicity.