The game between molecular photoredox catalysis and hydrogen: The golden age of hydrogen budge

Abstract

The corroboration between the transition metal catalysts and photocatalysts also termed as metalla-photocatalysis has dispensed new directions to the contemporaneous synthetic chemists in revolutionizing our chemical manufacturing set-ups. In new cooperative alliance facilitated by advanced materials providing novel synthetic protocol for facile access to photoexcited reactive radical intermediates under moderate reaction conditions. These transition metal molecular photoredox catalysts cooperatively interact with another metal catalysts, organocatalysts or semiconductor photocatalysts to effectively promote selective organic synthesis. Recently, hydrogen borrowing reactions like transfer hydrogenation and acceptorless dehydrogenation reactions have been critically evaluated for more sustainable and benign chemical manufacturing. Furthermore, acceptorless dehydrogenation or borrowing hydrogen reactions have received considerable attention for the fabrication of organic molecules for eco-friendly and benign protocol for the energy storage and transport. Therefore, binary and ternary photoredox catalytic systems have been developed for clean chemical manufacturing and energy storage and transport. The present review article focuses on the recent developments in the applications of the photoredox catalysts for transfer hydrogenation and acceptorless dehydrogenation reactions.