Cu-Mediated Syntheses of N-Fused and Ring-Modified Trithiahexaphyrins

The reaction of the antiaromatic [28]trithiahexaphyrin (TTHP) with CuI in DMF gives a novel fused‐ring trithiahexaphyrin with the elimination of a chloride on a dichlorophenyl ring and bond formation to the outward oriented pyrrolic nitrogen to form a 5,5,6‐tricyclic internal ring system. The NMR spectra, which display characteristics of an antiaromatic compound, agree with the proposed structure. Meanwhile, reactions of TTHP with amines in the presence of CuI give amino‐group‐inserted hexaphyrins with the amino nitrogen joined to a β‐thiophenic carbon and the α‐carbon of the alkylamine cyclized to the inward pyrrolic nitrogen to form a 5,7,5‐tricyclic rings. The crystal structure of the fused‐ring product indicates a rectangular geometry with a tilted tricyclic ring system, while the ring‐modified TTHP‐DMA complex gives a triangular trithiahexaphyrin core. This report demonstrates methods to incorporate functionalized heterocyclic rings into expanded porphyrins. The CuI‐mediated reaction of [28]trithiahexaphyrin with amines gives N‐fused and azamethylene‐inserted trithiahexaphyrins. This report demonstrates methods to incorporate functionalized heterocyclic rings into expanded porphyrins (two examples are shown here).