Study On The Biginelli-type Condensation Reaction And Mannich Reaction Catalyzed By Lanthanide Compounds

The Lanthanide compounds catalyzed syntheses of several kinds of azacompound are studied in this thesis, which is composed with three parts as follows:1. The Biginelli-type condensation of aromatic aldehyde, urea or thiourea with cyclopentanone is effectively catalyzed by ytterbium chloride affording benzylidene heterobicyclic pyrimidine-2-one in moderate to excellent yields. The reaction proceeds smoothly under solvent-free condition without rigorous exclusion of oxygen and moisture. The YbCl3 catalyzed condensation of aromatic aldehyde, cyanoacetamide and cyclopentanone, which gives a new type of benzylidene heterobicyclic pyridine-2-one, is explored. The effect of reaction conditions upon this reaction is investigated.2. The application of KI as additive for ytterbium chloride catalyzed reactions, including the synthesis of 1,5-benzodiazepine, synthesis ofα-amino phosphonate and Mannich reaction of benzaldehyde, aniline and acetophenone, is explored. It can be concluded that the activity of YbCl3 is improved in the presence of KI and the mechanism is discussed basing on an active intermediate isolated from the YbCl3/KI mixture.3. The Mannich reaction of aromatic aldehyde, aromatic amine and cyclopentanone catalyzed by Yb(OTf)3 is explored. The effect of various solvents and ligands upon this reaction is examined.