Emerging perylene diimide-based photocatalysts: status and trends in organic synthesis

Abstract

Perylenediimide (PDI)-based photocatalysts constitute a transformative breakthrough in synthetic chemistry, distinguished by their unique dual-photon activation mechanism that surpasses conventional single-photon systems. Through consecutive photoinduced electron transfer (conPET), PDI radical anions (PDI˙⁻) can absorb a second visible photon to generate excited radical anions (PDI˙⁻*) with extraordinarily negative oxidation potentials reaching −2.0 V vs. SCE, enabling challenging activation of chemically inert bonds. The strategic three-axis functionalization approach targeting imide, bay, and ortho positions provides unprecedented control over photophysical properties, redox behavior, and catalytic performance, establishing definitive structure–activity relationships. This mini-review demonstrates exceptional synthetic utility across a broad spectrum of transformations, encompassing aryl halide reductions, fluoroalkylation processes, electrophotocatalytic C–F bond functionalization, sulfoxide reduction, controlled radical polymerization, and radical cyclization reactions, while comprehensively addressing fundamental concepts, PDI design principles, mechanistic frameworks, and future research directions in this rapidly advancing field.