Recent advances in semi-heterogenous photocatalysis in organic synthesis

Semi-heterogeneous photocatalysis has emerged as a powerful and productive platform in organic chemistry, which provides mild and eco-friendly conditions for a diverse range of bond-forming reactions. The synergy of homogeneous catalysts and heterogeneous catalysts inherits their main advantages, such as higher activities, easy separation and superior recyclability. In this review, we summarize the recent advances in recyclable semi-heterogenous protocols for the light promoted bond-forming reactions and identify directions for future research according to the different photocatalysts/metal/redox catalysts involved. Notably, this review is not a comprehensive description of reported literature but aim to highlight and illustrate key concepts, strategies, reaction model, reaction conditions and mechanisms.