Biginelli Reaction Using a New Chiral Ytterbium Catalyst

Significance

Multicomponent reactions offer advantages due to their atom economy and they provide a good means for combinatorial chemistry. The authors report a highly enantioselective, three-component reaction yielding dihydropyrimidines. Hexadentate ligand 1 was developed to provide a chiral environment for the highly coordinating lanthanide metals. Importantly, many aldehydes are compatible for this reaction and provide high yields and high enantioselectivities. Various substituents on the aryl aldehydes are tolerated (Cl, Br, OH, NO-₂ etc) and phenylacetaldehyde and furfural also give good results. Urea and thiourea are both good substrates making the number of compounds attainable even greater.