2.3.4.5- Tetrafluorophenyl ester

Once released from the resin, the 3-aminobenzothiazepine derivatives could be further reacted with resin-bound tetrafluorophenyl ester of carboxylic acids to form amides (Scheme 6). Carboxylic acids were loaded... 

Example of Reaction of 1-Benzyl-3-amino-1,5-benzothiazepine with Resin-Bound Tetrafluorophenyl Esters... 

These compounds have been synthesized421 from the corresponding tri- -butylstannyl tetrafluorophenyl esters (equations 200 and 201). The labelled products 277 and 278 have... 

An alternative approach utihses the concept of catch-and-release whereby one of the reactants is first attached to the solid phase by an activated bond that is subsequently cleaved by exposure to a conjugate reactant. For example, in Figure lb, the carboxylic acid is initially immobilised as a tetrafluorophenyl ester. Although intrinsically stable, the activated ester is highly susceptible to nucleophihc cleavage, and in the presence of a substoichiometric amount of amine, the desired carboxamide product is cleanly released into solution. 

The same study revealed the unfavorable effect of substitution at both carbon atoms which are ortho to the phenoUc hydroxyl. Hence, the so far untested 2,3,4,5-tetrachlorophenyl and 2,3,4,5-tetrafluorophenyl esters... 

F]fluoronicotinic acid 2,3,5,6-tetrafluorophenyl ester 1/10/60-70 One-step synthesis Olberg etal. (2010)... 

Mass spectrometric splitting of substituents and ring fragments from TPs is exemplified in Table 11. In a similar way fragmentation of tetrafluorophenyl TP carboxylic ester 4 mainly proceeds by elimination of fluorine, decomposition of the ester group, cleavage of tetrafluorophenyl, and elimination of hydrocyanic acid (01RJOC570). 

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