Multi-walled carbon nanotubes functionalized with a palladium(II)-Schiff base complex: A recyclable and heterogeneous catalyst for the copper-, phosphorous- and solvent-free synthesis of ynones

The air-moisture stable and reusable multi-walled carbon nanotubes (MWCNTs) functionalized with a palladium(II)-Schiff base complex was synthesized by covalently anchoring a hydroxyl functionalized palladium(II)-Schiff base complex to modified MWCNTs. This heterogeneous catalyst exhibited effective catalytic activities by affording ynones in excellent yields from coupling reactions of acid chlorides with terminal alkynes under copper-, phosphorous- and solvent-free conditions in air. (c) 2012 Elsevier B.V. All rights reserved.