Visible-Light-Induced CdSeS/CdZnSe/ZnSe/ZnS Quantum-Dot-Catalyzed Three-Component Reaction for the Synthesis of α‑(4-Pyridyl)benzylaniline Derivatives

Using recyclable CdSeS/CdZnSe/ZnSe/ZnS core/shell quantum
dots
(QDs) as a photocatalyst under visible light irradiation, the synthesis
of α-(4-pyridyl)benzylaniline derivatives was achieved through
a three-component reaction. These reactions offer advantages such
as low catalyst loading, wide substrate scope, high yield, mild reaction
conditions, and easy scalability. They have been successfully applied
for the derivatization of natural amino acids and pharmaceutical late-stage
structural modification. Importantly, this core/shell QD exhibits
a remarkably high turnover number (TON) of 2.27 × 105 and can be easily recovered and recycled in the reaction for more
than 5 times without significant loss of catalytic activity. Mechanistic
studies reveal that thiols/thiophenols in the reaction serve as proton
donors, facilitating the reduction of cyanopyridine and the in situ form of imine.