Abstract
In this account, we survey our work on the use of transition metal nanoparticles as catalysts in Pauson-Khand-type reactions. Cobalt nanoparticles and Co/Ru, Co/Rh, and Co/Pd heterobimetallic nanoparticles have been used in Pauson-Khand-type reactions and related tandem reactions. In the case of Co/Ru nanoparticles, pyridylmethylformate can be used instead of carbon monoxide. We have developed environmentally friendly processes. The use of Co/Rh heterobimetallic nanoparticles allows the development of a new type of [2+2+1] cycloaddition of an α,β-unsaturated aldehyde with an alkyne.
1 Introduction
2 Cobalt on Mesoporous Silica: The First Heterogeneous PKR Catalyst
3 Colloidal Cobalt Nanoparticles
3.1 The First Use of Transition Metal Nanoparticles in the PKR
3.2 The First Catalytic PKR in Aqueous Media: Water-Stabilized Colloidal Cobalt Nanoparticles
4 Immobilized Cobalt Nanoparticles on Charcoal
4.1 Pauson-Khand Reaction
4.2 The Catalytic Reductive Pauson-Khand Reaction
5 Heterobimetallic Nanoparticles
5.1 Ru/Co Heterobimetallic Nanoparticles: Catalytic Pauson-Khand Reactions in the Presence of Pyridylmethylformate
5.2 Rh/Co Heterobimetallic Nanoparticles: Catalytic Pauson-Khand-Type Reaction between Alkynes and Olefinic Aldehydes
5.3 Palladium and Cobalt Nanoparticles Immobilized on Silica: One-Pot Synthesis of Bicyclic Enones by Catalytic Allylic Alkylation and Pauson-Khand Reaction
6 Use of a Combination of Cobalt Nanoparticles and Pd(II) Complex as a Catalyst in the Synthesis of Fenestranes
7 Conclusion
Key words
Pauson-Khand reaction - cobalt - heterobimetallic - nanoparticles - heterogeneous catalysis