New synthetic strategy for diporphyrins: Pinacol coupling-rearrangement

摘要

A new peak for porphyrins! A new approach to methylene-bridged diporphyrins has been explored, which consists of SmI_2-mediated pinacol coupling followed by BF_3-assisted pinacol-to-pinacolone rearrangement (see scheme). Diporphyrin 1 can further undergo multiple, dehydrative C-C bond formation to yield tetrahydropentalene-fused porphyrin dimer 2 with a rigid gable structure.