The Ultrasmall Palladium Nanoparticles Catalyzed Telomerization of CO 2 with 1,3‐Butadiene at Room Temperature: Selective Synthesis of δ ‐Lactone

An efficient method for the selective synthesis of δ ‐lactone from CO 2 and 1,3‐butadiene was developed by using ultrasmall palladium nanoparticles as a catalyst for the first time. Palladium nanoparticles (1.90±0.39 nm) were generated in situ in the presence of Pd(acac) 2 , tetrabutylammonium acetate (TBAAc), and PPh 3 as the precatalyst, stabilizer, and reductant, respectively. Maximum yield (86 % with 96 % selectivity) with satisfactory conversion (89 %) and turnover number (1271) was achieved under mild conditions.