Amine-mediated synthesis of amides from 1,3-dicarbonyl compounds through a domino diazo transfer/aminolysis process

Abstract The dual role of amines as both catalysts and substrates for the synthesis of diazo compounds or carboxamides from 1,3-dicarbonyl compounds is described herein. In the presence of a suitable diazo transfer agent, primary and cyclic secondary amines act as basic catalysts for the diazo transfer reaction to malonates, β -keto esters, and β -diketones. Depending on the structure of the 1,3-dicarbonyl compound and the nucleophilicity of the amine, the resulting α -diazo- β -keto ester undergoes cleavage of the acyl group to give amides. A multifunctionalized γ -azido- α -diazo- β -keto ester was cleanly prepared in good yields by this one-pot protocol under practical and safe conditions, being employed in a Knoevenagel-type condensation with aromatic aldehydes to give densely functionalized diazo azido compounds. Further treatment of these unsaturated γ -azido- α -diazo- β -keto esters with primary amines readily furnished the corresponding α -azidocinnamamides in high yields, which were used in the synthesis of novel indole-2-carboxamides through the rhodium-catalyzed intramolecular C H insertion.