ИСТИНА

Norbornene, norbornadiene and their derivatives have become important objects of modern chemistry and chemical engineering. These compounds have found wide application in medicine, agriculture, microelectronics, rocket technology and in the production of polymeric materials with unique properties, as well as solar energy converters and efficient gas separation membranes.[1] The incorporation of fluorine into the target molecule changes some of its important features: lipophilicity, solubility, receptor binding, metabolism, membrane permeability, acid-base characteristics aconformational properties. All of these features are considered in the design of new drugs and materials. [2] This work is devoted to the synthesis of novel fluorine-containing norbornenes and subsequent transformation them into the corresponding mono-fluorinated norbornadienes. The starting β-fluoro-β-nitrostyrenes were prepared according to the previously developed method (Scheme 1), based on the radical nitration of 2-bromo-2-fluorostyrenes. [3] 2-Bromo-2-fluorostyrenes, in turn, were obtained by the reaction of catalytic olefination from the corresponding aromatic aldehydes. [4]The Diels-Alder reaction of β-fluoro-β-nitrostyrenes with cyclopentadiene results in monofluorinated norbornenes (Scheme 2). The subsequent eliminations of HNO2 from the resulting adducts by t-BuOK give the corresponding norbornadienes.This work was supported by the Russian Science Foundation (RSF) (Grant No. 17-73-10358). This work was partially supported by the Russian Federation President Grant for leading scientific schools № 4687.2018.3. [1] V.R.Flid, M.L.Gringolts, R.S.Shamsiev, E.Sh.Finkelshtein. Russ. Chem. Rev., 2018, 87 (12) 1169 -1205 [2] Chem. Rev. 2015, Special Issue Fluorine Chemistry, 2, 563-1296 [3] V. A. Motornov, V. M. Muzalevskiy, A. A. Tabolin, R. A. Novikov, Yu. V. Nelyubina, V.G. Nenajdenko, S. L. Ioffe, J. Org. Chem. 2017, 82, 5274–5284. [4] A. V. Shastin, V. M. Muzalevsky, E. S. Balenkova, V. G. Nenajdenko, Mendeleev Commun. 2006, 16, 178−180