TIBAL‐Assisted Copper‐Catalyzed Ketone‐Amine‐Alkyne (KA 2 ) Reaction for Preparation of α‐Tertiary Propargylamines in Mild Conditions

ABSTRACT The addition of 0.6 equivalent of TIBAL promotes copper‐catalyzed KA 2 reaction in dichloromethane at room temperature. Alkyl‐ and aryl‐substituted terminal alkynes, α,ω‐diynes, a number of secondary amines (piperidine, pyrrolidine), and a number of ketones (cyclohexanone, cyclopentanone, acetone, 2‐octanone) were involved in the KA 2 reaction to prepare α‐tertiary propargylamines in good yield. The reaction with α,ω‐diynes leads to selective formation of the products of mono‐aminomethylation.