Heterocycles immobilized ligands

Polymer-immobilized complexes with heterocyclic ligands as catalysts 92UK257. 

In 1995 Schwarz et al.159 described novel heterocyclic structures able to adsorb selectively immunoglobulins. The structures contained sulfur and nitrogen. Reported ligands were 2-mercapto-pyridine,2-mercapto-pyrimidine, and mercapto-thiazoline. These structures were chemically immobilized on silica and agarose beads using epoxy-activated matrices. Binding capacities for silica based material were about 25 mg of IgG per milliliter of resin, while for agarose beads it was about 18 mg/mL. 

Heterocycles as reagents and ligands in immobilized heterogeneous catalysts 95MI1. 

N-Heterocyclic carbenes as highly efficient ligands in homogeneous and immobilized metathesis ruthenium catalytic systems 05ARK(10)206. 

Blechert et al. described the covalent bonding of Grubbs and Hoveyda-Blechert type metathesis catalysts to a support material via the N-heterocyclic carbene (NHC) ligands [33-35]. They used a Merrrfield-type resin as the polymeric backbone of the immobilized catalysts (cf. Figure 3a,b)). 

The nature of ligands, such as Boxs, phosphines, and N-heterocyclic carbenes (NHC), bound to a transition metal center usually afiects the selectivities and reaction rates in the organic reactions. Styring et al. described the preparation of a Pd (Il)-salen complex immobilized on Merrifield resin (42). The polymer catalyst facilitated the Suzuki-Miyaura cross-coupling reaction in a continuous-flow system (Scheme 7.32) [130]. The reactor continuously afforded biaryl adducts (43) from aryl... 

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