Copper nanoparticles stabilized on nitrogen-doped carbon nanotubes as efficient and recyclable catalysts for alkyne/aldehyde/cyclic amine A3-type coupling reactions

Metallic copper nanoparticles have been efficiently dispersed and stabilized on nitrogen-doped carbon nanotubes. They are about 8-10 nm in diameter and highly resistant against bulk oxidation. Their catalytic activity and recyclability have been investigated in A(3)-type coupling reactions for the synthesis of propargylamines. It was easily possible to prepare diastereomerically pure derivatives of proline and to efficiently recover and reuse the supported catalyst several times. (c) 2012 Elsevier B.V. All rights reserved.