Covalent primary alcohols

This is a composite of 1 % cross-linked polystyrene and covalently attached polyethylene glycol (PEG) (2000-3000 Da). One form, sold under the name TentaGel (Rapp Polymere), is made by polymerizing ethylene oxide on to a primary alcohol located on the cross-linked polystyrene [22,23], A second form, sold under the name PEG-PS (Perseptive), is made by attaching, through the formation of an amide bond, an already formed amino terminal PEG chain (Jeffamine) to 1% cross-linked polystyrene [24], The loading capacities for both types of supports are typically in the range of 0.2-0.3 mmol amine/g resin. 

Machida et al. presented a method for the immobilization of CCE on silica gel in 1998 [45]. They reported the covalent binding of (+)-(18-crown-6)-tetracarboxylic acid to 3-aminopropylsilanized silica gel and the prepared CSP was tested to separate enantiomers of amino acids, amino alcohols and other drugs (containing primary amino group). In 1998, the same CSP was prepared by Hyun et al. [46]. The developed CSP was used extensively for the chiral resolution of a variety of racemic compounds having a primary amino group... 

In 1998, Machida et al. [45] and Hyun et al. [46] developed a new CCE-based CSP (covalently bonded to silica gel see Sect. 8.2). This CSP was used successfully for the chiral resolution of certain racemic compounds using a variety of mobile phases. The most important applications of this CSP are for the resolution of amino acids, amino esters, amino alcohols, amines, amides, quinolone antibacterials, and other drugs having primary amino groups [46-51,64,65]. The typical chromatograms of the chiral resolution of amino acids on (+)-(18-crown-6)-2,3,ll,12-tetracarboxylic acid CSP are shown in Figure 4. The enantiomeric resolution of the racemic compound on CCE-based CSPs are listed in Table 2. There is no report available on the chiral separations at the preparative scale using these CSPs. 

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