Photosensitization and Photocatalysis—Perspectives in Organic Synthesis

Abstract

Photochemical sensitization and photocatalysis have very similar definitions and are closely related. Each of the two terms are preferentially used in different scientific communities. Three types of processes are discussed: (1) sensitization involving energy transfer, (2) photocatalysis in which hydrogen abstraction plays a key role, and (3) photoredox catalysis in which electron transfer is involved. The processes are discussed in connection with [2 + 2] photo-cycloadditions and C–H activation, which are of particular interest for organic synthesis.