Amidation Of Ester With Amine Catalyzed By Lanthanide/Alkali Metal Complex

The amidation of esters with amines catalyzed by lanthanide metal complexes were discussed in our research,a kind of lanthanide/alkali alkoxide clusters for the reaction of esters with aliphatic amines were first explored in detail.In addition,the catalytic behavior of lanthanide amides and the sodium alkoxide complex?NaOCH₂CF₃?in the transformation between esters and aromatic amines were also investigated.Main results were as follows:1.Reaction between sodium alkoxide NaOCH₂CH₂NMe₂,LnCl₃ and NaOH in 6:1:1molar ratio afforded the cluster Nd₂Na₈?OCH₂CH₂NMe₂?₁₂?OH?₂?1?.Reaction of sodium alkoxide NaOCH₂CF₃ with LnCl₃ in 7:1 molar ratio afforded the cluster Ln₂Na₈?OCH₂CF₃?₁₄?THF?₆?Ln=Nd?2?,Y?3?,La?4??.Complex 4 hasn't been reported before.This complex was determined by NMR spectroscopy and elementary analysis.A rough X-ray determination showed its structure was identical to that of the reported complex Nd₂Na₈?OCH₂CF₃?₁₄?THF?₆.2.The catalytic activity of La₂Na₈?OCH₂CF₃?₁₄?THF?₆ in the amidation of esters with aliphatic amines was investigated.Various reaction conditions were screened such as reaction time,temperature,catalyst loading and so on.The obtained optimized conditions involved treating an ester with an amine in 1:1.2 ratio at 80 ^oC for 6 h using 0.5 mol%La₂Na₈?OCH₂CF₃?₁₄?THF?₆ as catalyst under solvent free condition.Substrates scope implied that this catalyst was applicable for diverse esters and amines.3.The catalytic activity of La₂Na₈?OCH₂CF₃?₁₄?THF?₆ in the polyamidation of diesters with diamines was investigated.The results suggested that different kinds of polyamides can be synthesized in quite high yields,but we still failed to measure the molecular weight of them after attempting various methods.4.The catalytic performance of easily available lanthanide amides RE[N?SiMe₃?₂]₃??-Cl?Li?THF?₃ in the reaction of esters with aromatic amines was investigated,which showed that amides can be smoothly synthesized with 30 mol%La[N?SiMe₃?₂]₃??-Cl?Li?THF?₃ under 30 ^oC within 20 min.This system was equipped with good generality and the activity of aromatic esters was far beyond that of aliphatic ones.aromatic amines was more applicable than aliphatic amines and the activity of secondary amines was much higher than that of primary ones.Although this process can be completed under mild condition in short time,the high loading of catalyst cannot be ignored.5.The catalytic activity of Na OCH₂CF₃ in the amidation of esters with aromatic amines was investigated.Through the optimization of the reaction condition,it was found that various aromatic amines can be treated with esters to afford the corresponding amides catalyzed by 8 mol%of NaOCH₂CF₃ at 80 ^oC in moderate to excellent yields.