Covalent using inorganic supports

Probably the first non-covalent immobilization of a chiral complex with diazaligands was the adsorption of a rhodium-diphenylethylenediamine complex on different supports [71]. These solids were used for the hydride-transfer reduction of prochiral ketones (Scheme 2) in a continuous flow reactor. The inorganic support plays a crucial role. The chiral complex was easily... 

Since enzymes are not soluble in organic solvents, it is not necessary to immobilize them by covalent attachment to solid supports a simple adsorption or ion exchange may be used. Many supports can be utilized, inorganic (controlled-pore glass, silica, Celite, etc) as well as organic (ion exchange resins, polypropylene, etc)... 

Type I A metal ion, a metal complex or metal chelate is connected with a linear or crosslinked macromolecule by covalent, coordinative, chelate, ionic or Ti-type bonds (Figure 1). This type I is realized by binding of the metal part at a linear, crosslinked polymer or at the outer or interior surface of an inorganic support. Another possibility uses the polymerization or copolymerization of metal containing monomers. 

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