Photon upconversion, an anti-Stokes process that elevates photon energy, has become indispensable in photonic materials and optoelectronic devices. Inspired by this physical phenomenon, chemists have recently transposed its fundamental concept to organic catalysis, establishing electron upconversion as an innovative catalytic paradigm. The thermodynamic and kinetic advantages of electron upconversion originate from two key features: (1) Radical transformations exhibit significantly reduced energy release and accelerated reaction rates compared to ground-state processes; (2) The upconverted intermediates complete catalytic cycles via facile electron transfer mechanisms. Three principal electron upconversion strategies have been developed: molecular dissociation (e.g., homolytic bond cleavage), molecular association (e.g., three-electron bond formation), and super-electron-donor systems. These groundbreaking approaches have demonstrated remarkable efficacy in pivotal organic transformations including C—N cross-coupling and Si—Si bond activation, opening new avenues for sustainable catalysis development. This article provides a comprehensive discussion of the theoretical mechanisms (including thermodynamic and kinetic fundamentals), reaction types, and applications in catalytic synthesis, while also summarizing cutting-edge developments in related fields.

Key words: electron upconversion, dissociation, association, super-electron-donors, reductants