N-heterocyclic Carbene(Cu) Synergistic Photothermal Hydrogen Release Involving Double Hydrogen Transfer Catalyzed by Porphyrin(Cu)-Based Conjugated Microporous Polymers for Efficient Quinoline Hydrogenation

Abstract

Photothermal-driven double hydrogen transfer (DHT) strategies are highly desirable for boosting the hydrogen utilization efficiency of ammonia borane complexes and enabling green hydrogen evolution. In this work, three porphyrin-based CMPs, namely Im-PCMP, NHC(Cu)-PCMP and NHC(Cu)-PCMP(Cu), were synthesized via Suzuki-Miyaura coupling reaction (Nheterocyclic carbene, NHC). NHC(Cu)-PCMP(Cu) showed outstanding catalytic activity in the photothermal reductive hydrogenation of quinoline and its derivatives with high yields and selectivity. The isotopic labeling and control experiments revealed that (1) outstanding photothermal conversion efficiencies (η = 79%) of NHC(Cu)-PCMP(Cu), attributed to the synergistic effects of metal-carbene and porphyrin metallization via bimetallic regulating strategies; (2) enhanced activation performance for the N-H...H-B bond through NHC(Cu)-mediated cooperative catalysis; (3) effective DHT reductive hydrogenation of quinoline and its derivatives with t-BuNH2BH3 as hydrogen donors through heterogeneous photothermal process.