The use of water
in organic synthesis draws attention to its green
chemistry features and its unique ability to unveil unconventional
reactivities. Herein, literature about the use of water as a reaction
medium under visible-light photocatalytic conditions is summarized
in order to highlight challenges and opportunities. Accordingly, this
Synopsis has been divided into four different sections focused on
(1) the unconventional role of water in photocatalytic reactions,
(2)in-/on-water reactions, (3)
water-soluble photocatalysts, and (4) photomicellar catalytic systems.