Pyrylium salts acting as both energy transfer and electron transfer photocatalysts for E → Z isomerization of activated alkenes and cyclization of cinnamic or biaryl carboxylic acids

Abstract

2,4,6-Triarylpyrylium salts are stable, readily available and cheap. However, only their electron transfer oxidation ability has been explored. We herein report that they could perform both energy transfer and electron transfer activation modes for the photocascade E → Z isomerization/cyclizations, E → Z isomerization of activated alkenes and oxidative cyclizations.