Catalytic acceptorless complete dehydrogenation of cycloalkanes

Abstract

The advancement of an effective hydrogen liberation technology from liquid organic hydrogen carriers, particularly cycloalkanes such as cyclohexane and methylcyclohexane, holds significance in realizing a hydrogen-centric society. However, the attainment of homogeneous catalytic acceptorless dehydrogenation characterized by elevated selectivity for thorough aromatization under mild conditions remains unrealized. In this study, a catalyst system, facilitated by a double hydrogen atom transfer processes, has been devised for the catalytic acceptorless dehydrogenation of inert cycloalkanes at ambient temperature under visible light irradiation. Through the synergistic utilization of tetrabutylammonium chloride and thiophosphoric acid hydrogen atom transfer catalysts, successful catalytic acceptorless dehydrogenation with comprehensive aromatization has been accomplished with potential liquid organic hydrogen carrier candidates and showcased high functional group tolerance. The development of hydrogen atom transfer (HAT) in homogeneous catalytic acceptorless dehydrogenation (CAD) with selectivity for thorough aromatization under mild conditions remains challenging. Here, the authors propose a catalyst system that facilitates a double hydrogen atom transfer (HAT) processes for the CAD of inert cycloalkanes at ambient temperature under visible light irradiation.