Synthesis of tetrasubstituted propargylamines from cyclohexanone by solvent-free copper(ii) catalysis†
Abstract
Copper(II) chloride catalyzes the three-component coupling of cyclohexanone, amines, and alkynes to produce tetrasubstituted propargylamines. As a wide range of substrates react without solvent, excess starting material, or other additives, water is the sole by-product. Studies demonstrate that this reaction is first order in copper, cyclohexanone, amine, and alkyne. These mild conditions allow for the first direct, catalytic synthesis of silyl-protected tetrasubstituted propargylamines.