Study On CO₂ Transformations Into Oxazolidinones Catalyzed By Quaternary Ammonium Salt And Acetylenic Acid Catalyzed By Lanthanide Carboxylate

Quaternary ammonium salt and DBU were used to catalyze the reaction of CO₂into oxazolidinones,and lanthanide complexes stabilized by amine-bridged bis?phenolato?ligands were used to catalyze the reaction of terminal alkynes with CO₂.The ligand used is?MeNCH₂CH₂NMe?[CH₂-?2-OH-C₆H₂-Bu₂^t-3,5?]₂,and abbreviated as L¹H₂.1.Synthesis of oxazolidinones from CO₂,epoxides and amines catalyzed by quaternary ammonium salt and DBU The reaction of CO₂,epoxides and amines to produce oxazolidinones catalyzed by quaternary ammonium salt and DBU was explored.The optimized reaction conditions were 5 mol%of TBAI as catalyst,1 equiv.of DBU as additive,115°C and 1 atm of CO₂.A series of amines and epoxides were converted to the corresponding products in moderate to excellent yields?72%to 95%?.2.Synthesis of lanthanide carboxylate complexes and their catalytic property for the reaction of alkynes with CO₂Reaction of L¹H₂,NdCp₃?THF?and PhCOOH in a 1:1:1 molar ratio in THF gave the corresponding neodymium complex[L¹Nd?OOCPh??THF?]₂?1?in good yield.The structure of complex 1 was determined by single-crystal X-ray diffraction.The reaction of terminal alkynes with CO₂ catalyzed by lanthanide carboxylates was explored,and the optimized reaction conditions are 1.5 mol%of complex 1 as catalyst,2 equivalent of Cs₂CO₃ as base,DMSO as solvent,60 ^oC,1 atm,12 h.A series of terminal alkynes were converted to the corresponding acetylentic acids in moderate to excellent yields.