Surface enriched palladium on palladium-copper bimetallic nanoparticles as catalyst for polycyclic triazoles synthesis

Transition-metal nanoparticles (NPs) gained interest as a catalyst due to their high reactivity and recyclability. Monometallic NPs are less catalytic active compared to homogeneous counterparts as less number of catalytic active metal atoms are present on the surface of NPs and metal atoms present in the core part of the NPs are not utilized. It is necessary to synthesize a stable, reusable, highly reactive and economic catalyst which contain a more number of catalytic active precious metal atoms on the surface of NPs. Here in we have synthesized metal-carbon bond stabilized, alloy structured Pd/Cu bimetallic nanoparticles using binaphthyl moiety as a stabilizer (Pd/Cu-BNP). The enrichment of catalytically active precious Pd atoms over inexpensive Cu on the surface was observed with a narrow size distribution of the nanoparticles (average diameter 3 ± 0.5 nm). The Pd/Cu-BNP was used as an efficient and recyclable catalyst for the synthesis of polycyclic triazoles through domino alkyne insertion and C[sbnd]H bond functionalization reaction sequence.