Method for preparing compounds containing difluoromethylene

Abstract

The invention relates to a method for synthesizing compounds containing difluoromethylene group, more specifically a method for synthesizing difluoromethylene (in fact difluorocyclopropyl) compounds. Monohalogendifluoromethyl trialkylsilane(RRR<c>SiCF2X) used as difluorocarbene reagent is reacted with olefin compounds containing double bond of carbon in the presence of the initiator with catalytic amounts for 2-20 hours to obtain compounds containing difluorocyclopropyl. The monohalogendifluoromethyl trialkylsilane used in the invention can be prepared easily, which is a highly effective new difluorocarbene reagent with a good universal adaptation.

Description

technical field [0001] The present invention relates to the synthetic method of fluorine-containing medicine, pesticide intermediate, is the first use of a halodifluoromethyltrialkylsilane (R a R b R c SiCF 2 X) A method for synthesizing difluoromethylene-containing compounds. Background technique [0002] The introduction of difluoromethyl or difluoromethylene into molecules can often effectively improve the physiological activity of organic molecules, so it has attracted more and more attention in the fields of medicine, pesticides and materials. ((a) Kirsch, P. Modern Fluoroorganic Chemistry: Synthesis, Reactivity, Applications; Wiley-VCH: Weinheim, 2004. (b) Organofluorine Compounds: chemistry and Applications; Hiyama, T., Ed.; Springer: New York, 2000. ) Using difluorocarbene as a difluoromethyl or difluoromethylene building block is a better way to achieve the above-mentioned purpose. [0003] The most cost-effective difluorocarbene precursor so far is Freon22 gas...

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Problems solved by technology

Trifluoromethyl metal compounds such as Me 3 SnCF 3 、PhHgCF 3 , BrZnCF 3 , BrCdCF 3 It can also be used as a carbene reagent, but its synthesis is relatively complicated and its toxicity is high, which greatly limits its application ((a) Seyferth, D.; Hoppe, S.P., J.Organomet.Chem., 1971, 26, 64. (b) Seyferth, D.; Hoppe, S.P; Darragh. K.V., J. Am. Chem. Soc. 1969, 91, 6536.)

Others such as CF 2 Br 2 ((a) Dolbier, W.R.; Burkholder, Jr. C R, J. Org. Chem., 1990, 55; 589; (b) Dolbier, W. R.; Wojtowicz, J. H.; Burkholder, C. R., J. Org. Chem., 1990 55, 5420; (c) Crabbe, P.; Cervantes, A.; Cruz A.; Galeazzi, E.; ), FSO 2 CF 2 COOH (Chen, Q.-Y.; Wu, S.-W.J. Fluorine Chem. 1989, 44, 433.), FSO 2 CF 2 COOSiMe 3 (Tian, ​​F.; Virginie, B.; Duan, J.X., Dolbier, W.R.Jr.; Chen, Q.Y., Org Lett., 2000, 2, 563.) also have certain applications, but generally do not have high general Adaptability and selectivity

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