Enantioselective Synthesis of Chiral Imidazolidine Derivatives by Asymmetric Silver/Xing-Phos-Catalyzed Homo-1,3-Dipolar [3+2] Cycloaddition of Azomethine Ylides

摘要

Enantioselective synthesis of chiral heterocyclic derivatives is an important and challenging topic in the field of synthetic chemistry. In this work, the first stereocontrolled dimerization-type homo-1,3-dipolar [3+2] cycloaddition reaction of glycine aldimino esters for creating new heterocycles bearing multiple stereogenic centers has been developed through chiral phosphine ligand-involved silver catalysis. A variety of chiral imidazolidines could be obtained with high yields and good diastereoselectivities as well as excellent enantioselectivities by em-ploying Xing-Phos as chiral phosphorus ligand. In addition, the silver/Xing-Phos-catalyzed homo-1,3-dipolar [3+ 2] cycloaddition reaction is also a facile and novel protocol for catalytic polymerization of bifunctional glycine aldimino esters to give chiral poly(imidazolidine)s with a very narrow molecular weight distribution.