Polymer-supported cobalt carbonyl complexes as novel solid-phase catalysts of the Pauson–Khand reaction

Abstract

Cobalt carbonyl complexes immobilised onto a 'polymerbound triphenylphosphine' solid support are effective and practical catalysts of the Pauson-Khand reaction.

Cobalt on Charcoal: A Convenient and Inexpensive Heterogeneous Pauson–Khand Catalyst

“…This compound is an adduct of a neutral phosphoselenide cage with copper iodide. [2] Lowering the annealing temperature of the starting materials, copper iodide, phosphorus, and selenium, yields (CuI)P 4 Se 4 , [3] in which phosphorus and selenium are arranged as polymers consisting of P 4 Se 3 cages, analogous to norbornane, bridged by selenium atoms. This finding is consistent with the behavior of free equimolar mixtures of phosphorus and selenium, that, at low temperatures, form a polymer [4] which depolymerizes at higher temperatures.…”

“…It has been recently discussed that this building unit can adapt to a given coordination necessity due to the flexibility of both the a(Cu-I-Cu) and the a(I-Cu-I) angles. [3] Typical measures for these rhomboids are, for example, the distance d(Cu-Cu) and the angles mentioned above. For (CuI) 2 P 8 Se 3 , the following In conclusion, cobalt on charcoal has been developed as an inexpensive, heterogeneous, and highly effective catalyst for intra-and intermolecular Pauson ± Khand reactions.…”

“…Recently we published [2] the first heterogeneous catalyst system for the Pauson ± Khand reaction based on cobalt on mesoporous silica. Polymer-supported cobalt carbonyl complexes have been reported [3] as catalysts of the intramolecular Pauson ± Khand reaction, but the catalytic activity was low. The cobalt on a mesoporous material system is a quite effective catalyst for the intramolecular Pauson ± Khand reaction, but displays low activity in the intermolecular Pauson ± Khand reaction.…”

Readily prepared polymer-supported molybdenum carbonyls as novel reusable and highly active epoxidation catalysts

“…It is anticipated that immobilization of molecular catalysts make them readily separable from reaction mixture, facilitate recycling of catalyst and reduce its toxicity and air sensitivity [2]. A variety of procedures for preparation of covalently bound metal carbonyls to amine or phosphine functionalized polymers have been previously reported [3][4][5][6][7][8][9]. However, despite their advantages, these systems frequently suffer from complicated preparation procedures.…”

Dendrons and dendritic catalysts immobilized on solid support: Synthesis and dendritic effects in catalysis

“…However, catalytic versions of the reaction, based on phosphine or phosphite ligands, were recently developed. 65 Both 4-and 2-diphenylphsphinobenzoate-bearing dendritic resins (generations 0 -3) were complexed with Co 2 (CO) 8 according to a literature procedure, 66 and the formed systems were tested in the intramolecular reaction of 1,6-enyne (Scheme 24). 53 Along with the regular Pauson-Khand cyclopentenone product, an Alder-ene byproduct was obtained in all experiments.…”