Abstract
An efficient method for the selective synthesis of delta-lactone from carbon dioxide and 1,3-butadiene was developed using palladium nanoparticles as the catalyst without any additional ligand. The highest yield (51% with 94% selectivity) was achieved using Pd(acac)(2) as the precatalyst in the presence of TBAAc as both reducing and stabilizing agent in acetonitrile at 70 degrees C. The palladium nanoparticles generated in situ could be easily recovered through a simple extraction process and reused three times without an obvious loss in activity. The TEM image showed the presence of (3.8 +/- 1.1) nm-sized palladium nanoparticles in the reaction mixture. (C) 2016 Elsevier Ltd. All rights reserved.