摘要
It remains challenging to achievevaluableplatformchemicals from lignin because of itscomplicated polymeric structure and inherent inert chemical activities.So far,only a fewexamples have been reported for the selective cleavage of C–C bonds in lignin due to their intrinsic inertness and ubiquity.Here,we present a simple and commercially available cerium(Ⅲ)chloride(CeCl_(3))-promoted photocatalytic depolymerization strategy to realize the simultaneous cleavage and amination ofC_(α)–C_(β)bond in a variety of lignin model compounds at room temperature.This procedure does not require any pretreatments and breakdown of C–O bonds or loss ofγ-CH_(2)OHgroup to generate aldehydes(up to 97%)and N-containing products(up to 95%)in good to excellent yields.Additionally,this CeCl_(3)-based photocatalyst system could maintain excellent catalytic performance even after 10 sequential cycles with newstarting materials.Moreover,this approach realizes the precise control over the reaction via switching the external light stimuli on/off.Further,this method is effective for the depolymerization of real lignin,thus affording the corresponding cleavage and amination products of C_(α)–C_(β)bonds.
基金
supported by the National Natural Science Foundation of China(grant nos.21975102,21871107,and 21774042).
