One‐Pot Synthesis of Butadiyne‐Bridged Bipyrrole Derivatives and Bisporphyrin

Butadiyne‐bridged bipyrroles were prepared from 2‐iodopyrroles and trimethylsilylacetylene through a facile one‐pot synthesis involving a modified Sonogashira coupling reaction and in situ aerobic oxidative coupling of the acetylenic pyrroles; the products were obtained in yields of 31–72 % depending on the substituents on the pyrrole. The acetylene‐bridged diacids obtained from the hydrolysis of the corresponding ester derivatives are highly stable, unlike most reported oligopyrrolic diacids. This protocol could be easily extended towards the synthesis of butadiyne‐bridged bisporphyrins. Butadiyne‐bridged bipyrroles are obtained from the corresponding iodopyrroles through a one‐pot strategy, which is subsequently applied to the synthesis of butadiyne‐bridged bisporphyrin in good yield. DBU = 1,8‐diazabicyclo[5.4.0]undec‐7‐ene, TMSA = trimethylsilylacetylene.