Facile synthesis of 9,10,19,20-tetraarylporphycenes

Abstract

A simple route was developed for the synthesis of 9,10,19,20-tetraarylporphycenes by combining both McMurry and oxidative synthetic strategies and using readily available precursors. The desired 5,6-diaryldipyrroethenes, which were prepared in multigram quantities over two steps, were used to prepare 9,10,19,20-tetraarylporphycenes under mild acid-catalyzed conditions. As 5,6-diaryldipyrroethene precursors can easily be prepared in multigram quantities, this method is useful for the preparation of meso-tetrarylporphycenes that contain different aryl substituents. The molecular structures of these macrocycles were determined by HRMS analysis as well as 1D and 2D NMR studies. The tetraarylporphycenes exhibited a strong Soret band at approximately 380 nm and three Q bands in the region of 580–655 nm. The tetraarylprophycenes are reasonably fluorescent and stable under redox conditions.