Fluorous fluorine content differences

It is noteworthy that the fluorine content differences can be generated by attaching either similar reaction domains to different fluorous tags [13] or the same fluorous tag to reaction domains of different sizes (Figure 7.1). For example, a class of fluorinated dendrimers with the same fluorinated domain (fluorous tag), G0-G3, can be separated from each other by fluorous HPLC because of the over 10% differences in their fluorine content (Figure 7.3). Comparing the HPLC profile of dendrimers on the fluorous phase with that on normal phase and reverse phase, it is clear that fluorous HPLC gives the best separation. 

This chapter aims to summarize our efforts to investigate the effects of fluorinated amino acid substitutes on the interactions with natural protein environments. In addition to a rather specific example concerning the interactions of small peptides with a proteolytic enzyme, we present a simple polypeptide model that aids for a systematic investigation of the interaction pattern of amino acids that differ in side chain length as well as fluorine content within both a hydrophobic and hydrophilic protein environment. Amino acid side chain fluoiination highly affects polypeptide folding due to steric effects, polarization, and fluorous interactions. 

In addition to the en route protocol described in Section 13.2.6 for the synthesis of pas-sifloricins, the use of redundant tags for the synthesis of fused-tricyclic hydantoins is another example of FMS in which the number of fluorous tags is less than that of components in the mixture. Since molecules for FMS have fluorine atoms both on the parent structure and on the tag, each component in the mixture has different total fluorine content - even the tag may be redundant. 

Third, fluorous HPLC is able to separate fluorous compounds from each other by decoding the fluorine content diflerences between fluorous compounds. The difference between FSG-based sohd-phase extraction and chromatography lies in the loading level of the samples. At a low loading level, the resolution of fluorous components increases and, therefore, multiple fractions with different fluorine contents can be collected as different components that is, fluorinated components... 

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