Polymer supported transition metal

There are several polymer supported transition metal hydrofomylation catalysts (42 ). Most are attached by phosphine ligation and suffer fron catalyst leaching. There are no n5-cyclo-pentadienyl half sandwich systems despite the potentially, clearly advantageous presence of the relatively strong Cp-metal bond (43,MO. Resin 5 was used in the following brief study in which the potential of polystyrene-supported CpCo(C0)2 to function as a hydrofomylation catalyst was tested. 

Sherrington, D. C. Polymer-supported transition metal complex alkene epoxidation catalysts. Spec. Publ. - R. Soc. Chem. 1998, 216, 220-228. 

Polystyrene-based resins have been used widely as supports for metal complex catalysts and other reactive species. These polymers, however, have a drawback in their limited thermo-oxidative stability [1,2]. The scope for application is therefore restricted, particularly in polymer-supported transition metal complex oxidation catalysts [3]. Consequently there is a need for the development of polymer supports with a much higher intrinsic thermo-oxidative stability. Polybenzimidazoles and polyimides are likely candidates in this respect. 

C. U. Pittman, Jr., Catalysis by Polymer-Supported Transition Metal Complexes, Chapter 5 in Polymer-Supported Reactions in Organic Synthesis, P. Hodge, D. C. Sherrington, Eds., pp. 249-291, Wiley, New York, 1980. 

Figure 1. Preparation of polymer-supported transition metal complexes by ligand exchange.

Oxidation of organic compounds using Hydrogen peroxide and tert.- BHP catalysed by polymer supported transition metal catalysts ... 

The author s own interest in this area includes new functional polymers for solid phase synthesis [11-13], polymers with molecularly imprinted substrate selectivity [14], polymer-supported transition metal catalysts [15], novel polymers of potential interest for electrocatalysis [16], targeting of colloidal drug carriers [17, 18], molecular composites [19], and biocompatible surfaces [20]. These studies have led to, among other things, a uniquely versatile method of polymer synthesis based on the chemistry of activated acrylates, i.e. polymer synthesis via activated esters. Various aspects of polymers and copolymers of activated (meth)acrylates have also been investigated in this and several other laboratories. 

A wide variety of polymers have been used to prepare polymer supported transition metal complexes for a variety of applications, as shown in Table I. 

Polymer supported transition metal catalysts Asymmetric hydroformylation or oxidation reactions d... 

Stability of Polymer-Supported Transition Metal Catalysts... 

In an effort to overcome the necessity for high-dilution techniques during palladium-mediated macro( clization reactions, the use of polymer-supported transition-metal complexes offers an attractive solution. Reaction concentrations of up to 0.5 mol dm can now be used. ... 

---