New types of asymmetrical bromonium salts [RF(RF′)Br]Y where RF and/or RF′ represent perfluorinated aryl, alkenyl, and alkynyl groups |
| |
Authors: | Hermann-Josef Frohn Matthias Giesen |
| |
Affiliation: | a Department of Chemistry, Institute of Inorganic Chemistry, University of Duisburg-Essen, Lotharstr. 1, D-47048 Duisburg, Germany b N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, SB RAS, Acad. Lavrentjev Ave. 9, 630090 Novosibirsk, Russian Federation |
| |
Abstract: | A series of previously unknown asymmetrical fluorinated bis(aryl)bromonium, alkenyl(aryl)bromonium, and alkynyl(aryl)bromonium salts was prepared by reactions of C6F5BrF2 or 4-CF3C6H4BrF2 with aryl group transfer reagents Ar′SiF3 (Ar′ = C6F5, 4-FC6H4, C6H5) or perfluoroorganyl group transfer reagents RF′BF2 (RF = C6F5, trans-CF3CFCF, C3F7C≡C) preferentially in weakly coordinating solvents (CCl3F, CCl2FCClF2, CH2Cl2, CF3CH2CHF2 (PFP), CF3CH2CF2CH3 (PFB)). The presence of the base MeCN and the influence of the adducts RF′BF2·NCMe (RF = C6F5, CF3C≡C) on reactions aside to bromonium salt formation are discussed. Reactions of C6F5BrF2 with AlkF′BF2 in PFP gave mainly C6F5Br and AlkF′F (AlkF′ = C6F13, C6F13CH2CH2), presumably, deriving from the unstable salts [C6F5(AlkF′)Br]Y (Y = [AlkF′BF3]−). Prototypical reactivities of selected bromonium salts were investigated with the nucleophile I-and the electrophile H+. [4-CF3C6H4(C6F5)Br][BF4] showed the conversion into 4-CF3C6H4Br and C6F5I when reacted with [Bu4N]I in MeCN. Perfluoroalkynylbromonium salts [CnF2n+1C≡C(RF)Br][BF4] slowly added HF when dissolved in aHF and formed [Z-CnF2n+1CFCH(RF)Br][BF4]. |
| |
Keywords: | Bis(perfluoroorganyl)bromonium salts Organyl(perfluoroorganyl)bromonium salts Aryldifluorobromane Perfluoroorganylboron difluorides Aryltrifluorosilanes NMR spectroscopy |
本文献已被 ScienceDirect 等数据库收录! |
|