In Situ Generation of Copper Nanoparticle‐Graphitic Carbon Nitride Composite for Stereoselective Transfer Semihydrogenation of Alkynes: Evaluation of Catalytic Activity Using Fluorescence‐Based High‐Throughput Screening

Herein, we present the effective synthesis of a copper nanoparticle‐graphitic carbon nitride (g‐C3N4) composite for the efficient (Z)‐selective transfer semihydrogenation of alkynes. A fluorescence‐based high‐throughput screening method was applied to identify the most synergistic support for in situ‐generated copper nanoparticles. The derived Cu(OAc)2/g‐C3N4 system exhibited more than five‐fold increase in the turnover frequency compared to the copper nanoparticle catalyst in the absence of g‐C3N4. Various alkynes were selectively reduced to the corresponding (Z)‐alkenes under mild reactions conditions, affording up to 99% isolated yields. The present work demonstrates a simple and cost‐effective method for the synthesis of a copper nanoparticle‐g‐C3N4 composite for the efficient (Z)‐selective transfer semihydrogenation of alkynes.