A 4-Dimethylaminopyridine-Catalyzed Aminolysis of β-Ketoesters. Formation of β-Ketoamides
作者:Janine Cossy、Annie Thellend
DOI:10.1055/s-1989-27383
日期:——
Alkyl 3-oxoalkanoates (ß-ketoesters) react with amines in the presence of a catalytic amount of 4-dimethylaminopyridine (DMAP) under mild conditions to form 3-oxoalkanamides (ß-ketoamides) in good yields.
A highly efficient and facile catalyst- and solvent-free one step amidation of β-ketoesters, without using any additional reagents, is described. Therefore, β-ketoamides are obtained in good to excellent yields by condensation of β-ketoesters with various primary or secondary amines. This eco-friendly protocol has been developed under microwave irradiation.
A multicomponent reaction of 1,3-dicarbonyls with 1,2-diamines and aromatic aldehydes is described for the direct stereoselective synthesis of 1,4-diazepane derivatives. Various reaction conditions were tested, including an efficient, user-friendly solvent- and catalyst-free procedure.
Cyclic β-ketoamides undergo a regioselective 1,2-addition to α,β-unsaturated aldehydes leading to synthetically valuable cycloalkenones by a stereoselective one-pot γ-allylidenation promoted by DBU in MeOH.
The stereoselective one-pot synthesis of polysubstituted 1,4-diazepine derivatives has been achieved via a new solvent- and catalyst-free multicomponent domino reaction from β-ketoamides. This green and experimentally simple sequence is conducted from easily accessible achiral starting materials, does not require any harmful reagents, and results in a high increase in molecular complexity and diversity. Moreover, water is the only byproduct liberated during the reaction.