G. Haufe, S. Suzuki, H. Yasui
Dec 3, 2012
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Influential Citations
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Angewandte Chemie
Abstract
The selective synthesis of fluorinated organic compounds and the investigation of their properties have become major topics in all fields of the chemical sciences, as well as in technological applications. Whereas methods for the formation of C F bonds have been developed from the beginning of organic fluorine chemistry, the application of C F bond cleavage in poly-fluorinated carbon compounds for the preparation of partially fluorinated molecules has been less developed. This is apparently due to the fact that C F bonds are the strongest that carbon can form. Research into the activation of C F bonds of arylfluorides has a long history, but aliphatic fluorides have been less frequently involved in such processes and quite forcing conditions, such as organometallic reagents or strong nucleophiles, have to be applied. Thus, the development of mild and effective methods for the activation of aliphatic C F bonds has become a stimulating topic in general organic chemistry. Although the C F bond activation of several aliphatic fluorides with lithium reagents, Brønsted acids, Lewis acids, transition metals, or Grignard reagents has been reported in recent years, 7] most of these methods require that the fluorine atom(s) should be bound in an activated position such as benzylic, allylic, a to a carbonyl (or an equivalent), on a halogenated carbon, and so on. C F bond cleavage in an unactivated aliphatic position under mild conditions is still a challenge, although the substitution of CH2F groups by phosphine groups using R2PLi was reported 30 years ago. Very recently, we have been able to substitute all three fluorines and another b-halogen substituent of b-trifluoromethyl-b-halostyrenes with primary amines to form vinylogous guanidinium salts. As part of our research program related to the development of biologically relevant fluorine-containing molecules, we have been interested in 3,5-diaryl-2-fluoromethyl-oxazolidin-2-ones (1). 3,5-Diaryl-2trifluoromethyl-oxazolidin-2-ones (2) are promising agrochemicals which can act as insecticides, acaricides, ectoparasiticides, and control agents for animal parasites. Although more than 4400 compounds related to 2 are registered in the SciFinder database (most of them patented), no monofluoromethyl analogues, 1, have yet been reported (Figure 1).