4-Fluoro-4- butanone dehydrofluorination

Comparable effects were observed in the catalysis of the dehydrofluorination of 4-fluoro-4-(p-nitrophenyl)-2-butanone using Mi-polymers or even Ml-pro-teins (see later) imprinted with suitable TSA templates. Focusing on the two sp3 hybridized carbons (C2 and C3) of the butanone which are converted to sp2 carbons as a result of dehydrofluorination, the search for the right TSA led to N-benzyl-AT-isopropylamine (Fig. 13) either containing a nitro-group [62] at the aromatic ring or not [63,64]. 

Fig. 14. Application of an AT-benzylisopropylamine imprinted MAA/EGDMA copolymer as catalyst for the dehydrofluorination of 4-fluoro-4-(p-nitrophenyl)-2-butanone in a batch reactor. Given is the substrate concentration versus time. The reaction was carried out at 50° C in 10 ml of a mixture of water and acetonitrile 1 1 (v/v), containing 5 mg of the substrate 4-fluoro-4-(p-nitrophenyl)-2-butanone (i. e., a final concentration of 2.4 mmol/1) and 500 mg MIP or non-im-printed control polymer (CP). Top use of MIP, 1. experiment ( ), 2. experiment ( ). Bottom use of CP, 1. experiment ( ), 2. experiment ( ). Reprinted with permission from Briiggemann O (2001) Anal Chim Acta 435 197. Copyright 2001 Elsevier Science...

The catalysis of some other reactions by imprinted polymers also showed promising results. The dehydrofluorination of 4-fluoro-4-(4-nitrophenyl)butanone... 

Better results were obtained for the catalysis of the dehydrofluorination of 4-fluoro-4-(4-nitrophenyl)butanone by Shea et al. [94] and Mosbach et al [147]. Shea used benzyl-malonic acid as the template to position two polymerizable amines in a definite arrangement in the cavity. After removal of the template, dehydrofluorination was enhanced by this catalyst by a factor of 8.6. 

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