Synthesis of 5-alkynyl bicycloporphyrins as a synthon of 5-ethynyl bicycloporphyrin

[Display omitted] •5-Alkynyl CP were obtained by Sonogashira coupling of TIPS-acetylene and 5-bromo CP.•The semiconductor characteristics of the synthesized 5-alkynyl BPs were evaluated.•BP dimer and 5-arylethynyl BPs were synthesized from 5-ethynyl CP. 5-Alkynyl bicycloporphyrins (5-alkynyl CPs) were obtained by Sonogashira coupling reaction of trimethylsilylacetylene and 5-bromo CP in low yield. Triisopropylsilylacetylene has low volatility and is bulky, and its use in place of trimethylsilylacetylene markedly improved the yields of 5-alkynyl CPs. The semiconductor characteristics of the synthesized 5-alkynyl benzoporphyrins (5-alkynyl BPs) were evaluated. We also synthesized BP dimer and 5-phenylethynyl BPs containing an ethynylbenzene derivative by coupling reaction and retro Diels-Alder reaction.