Turning CO 2 Into an Oxygen Donor: Photocatalytic Strategies for Alkene Oxidative Cleavage

Carbon dioxide (CO 2 ) has long been regarded as an abundant and sustainable one-carbon (C1) feedstock for chemical synthesis.However, most CO 2 utilization strategies exploit the carbon atom of CO 2 , whereas its oxygen atoms are usually treated as thermodynamically inert spectators.Despite its oxygen-rich composition, using CO 2 as an oxygen donor remains highly challenging because of its exceptional stability and strong C=O bonds.In a recent science report, Qin et al. demonstrated a conceptually distinct photocatalytic strategy in which CO 2 functions as an oxygen-atom source rather than merely a carbon source [1].By integrating Fe-centered CO 2 activation with photocatalytic oxygen transfer, the authors enabled the oxidative cleavage of alkenes using CO 2 as the sole oxygen source under ambient conditions.This conceptually distinct approach expands the role of CO 2 from a conventional C1 feedstock to an oxygen-atom source under photocatalytic conditions.Specifically, upon Fe-centered activation of CO 2 , Febound oxygen species are generated and act as the reactive oxidants, selectively transferring oxygen to alkene C=C bonds.Supported by comprehensive isotope-labeling, spectroscopic, and theoretical investigations, the work reveals the fundamental principles governing oxygen abstraction from CO 2 and establishes a new reaction platform for sustainable oxidation chemistry.Beyond demonstrating an efficient alkene cleavage reaction, this breakthrough introduces a new paradigm for CO 2 utilization, expanding its function from carbon incorporation to oxygen delivery and opening new horizons for photocatalytic organic synthesis.