Copper‐Catalyzed Diversity‐Oriented Three‐ and Five‐ Component Synthesis of Mono‐ and Dipropargylic Amines <i>via</i> Coupling of Alkynes, α‐Amino Esters and Aldehydes

Abstract

Abstract Mono‐ as well as dipropargylic amines were synthesized using α‐amino esters as inexpensive building blocks under a single catalytic system (copper bromide, 100 °C, 4 h, toluene) where the reactant ratio ( 1a / 2a / 3a ) acted as product specific switch. Both secondary (mono) as well as tertiary (di) propargylic amines formed via three‐ and five‐component coupling exhibited wide substrate scope with moderate to good yields and satisfactory diastereoselectivity in a few cases. The practical utility of the method is enhanced by providing a facile access to enantiopure propargylic amines via lipase‐catalyzed resolution along with synthesis of unsymmetrical dipropargylic amines, secondary propargylic amines bearing quaternary carbon centers and imidazolidin‐2‐ones. magnified image