Synthesis of Phenylenediethynylene-Containing Cyclophanes via Stepwise Cross-Coupling Reactions and their Transformation to Strained pi-Conjugated System

Abstract

Sonogashira-Hagihara cross-coupling reaction in a stepwise fashion enabled to synthesize precursors of paraphenyleneacetylene macrocycles in better yield than a one-pot fashion. This stepwise synthesis allowed to elaborate cyclophanes containing one metaphenylene or orthophenylene. When we carried out reductive aromatization reactions of cyclophanes with a tin-reagent and a fullerene, we observed the formation of pi-conjugated cyclynes as an inclusion complex with a fullerene.