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Reactions of Polyfluoroarenes with Me n E‐MMe 3 Reagents (Me n E = Me 2 As, Me 2 P, Me 2 N, and MeS; M = Si, Sn): Synthesis of Polyfluoroaryl Me n E Compounds
Author(s) -
Goryunov Leonid I.,
Shteingarts Vitalij D.,
Grobe Joseph,
Krebs Bernt,
Triller Michael U.
Publication year - 2002
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/1521-3749(200208)628:8<1770::aid-zaac1770>3.0.co;2-5
Subject(s) - trimethylsilyl , chemistry , reagent , medicinal chemistry , derivative (finance) , fluorine , organic chemistry , financial economics , economics
Trimethylsilyldimethylarsane Me 3 SiAsMe 2 was used as a reagent for the substitution of fluorine in polyfluoroarenes C 6 F 5 X (X = F, H, Cl) and C 5 NF 5 by the Me 2 As group. The reactions occur between 50 — 180 °C, either in benzene or without solvent, to give as a rule 4‐X‐1‐(dimethylarsano)tetrafluorobenzenes XC 6 F 4 AsMe 2 , ( 1—3 ) and 4‐dimethylarsano‐tetrafluoropyridine C 5 NF 4 AsMe 2 ( 4 ), respectively, in yields between 43 and 94 %. In the case of C 6 F 6 , also double substitution is observed affording 1, 4‐bis(dimethylarsano)tetrafluorobenzene 5 in addition to the monosubstituted derivative. The time and temperature dependencies of the reactions increase in the sequence: C 6 F 6 < C 6 F 5 H < C 6 F 5 Cl < C 5 NF 5 . The arsanes 1 and 4 were transformed to the potentially valuable bidentate ligands 1‐(dimethylarsano)‐4‐(dimethylphosphano)tetrafluorobenzene 6 and 4‐(dimethylarsano)‐2‐(dimethylphosphano)trifluoropyridine 8 by reaction with trimethylsilyl‐dimethylphosphane Me 3 SiPMe 2 . 6 reacts with oxygen to yield the corresponding phosphane oxide 7 . Trimethylsilyl‐dimethylamine Me 3 SiNMe 2 also was successfully tested as a reagent for the dimethylamination of polyfluoroarenes C 6 F 5 X [X = F, H, Cl, CF 3 , P(S)Me 2 ], 1‐P(S)Me 2 ‐4‐H‐C 6 F 4 and 4‐X‐C 5 NF 4 [X = F, PMe 2 , P(S)Me 2 ]. Sulfuration of the new Me 2 P derivatives 8 and 20 leads to the corresponding thiophosphanes 9 and 21 (Schemes 2 and 3). Furthermore, the recently reported very efficient one‐pot synthesis of Me 2 P substituted polyfluoroarenes (e.g. XC 6 F 4 PMe 2 with X = F, Me 2 PC 6 F 4 ) was extended to the preparation of Me 2 As and MeS derivatives of pentafluoropyridine using a mixture of Me 3 SnH, As 2 Me 4 (or S 2 Me 2 ) and C 5 NF 5 as precursors for the one‐pot reaction. The expected products 4‐(dimethylarsano)tetrafluoropyridine 4 and 4‐(methylthio)tetrafluoropyridine 22 , respectively, were obtained in 84 and 82 % isolated yields. The novel compounds were characterized by spectroscopic (NMR, MS) and analytical data. Compounds 5 , 7 , 9 and 21 could be isolated in form of single crystals and their structures have been studied by X‐ray diffraction.