Sustainable System for Hydrogenation Exploiting Energy Derived from Solar Light

Herein
described is a sustainable system for hydrogenation that
uses solar light as the ultimate source of energy. The system consists
of two steps. Solar energy is captured and chemically stored in the
first step; exposure of a solution of azaxanthone in ethanol to solar
light causes an energy storing dimerization of the ketone to produce
a sterically strained 1,2-diol. In the second step, the chemical energy
stored in the vicinal diol is released and used for hydrogenation;
the diol offers hydrogen onto alkenes and splits back to azaxanthone,
which is easily recovered and reused repeatedly for capturing solar
energy.