Reactions of halo‐ and dihaloadamantanes with nitromethane anions by the S_RN1 mechanism

Abstract

The reactions of 1-bromo-, 2-bromo-, 1,3-dibromo-and 1,4-dibromoadamantane with À CH 2 NO 2 anions were studied in DMSO and in liquid ammonia. The photostimulated reaction of 1-haloadamantane (1-AdX, X = Br, I) or 2-AdBr with À CH 2 NO 2 anions gave good yields of the substitution product 1-AdCH 2 NO 2 and 2-AdCH 2 NO 2 , respectively, in the presence of the enolate anions of acetone (entrainment conditions). On the other hand, 1-adamantanol was the main product of the reaction performed in DMSO without irradiation, but not in liquid ammonia. 1,3-Dibromo and 1,4-dibromoadamantane reacted with À CH 2 NO 2 anions under irradiation in the presence of the enolate anions of acetone. The first compound gave the disubstitution product 11, and the second the monobromo-substitution products 15 and 16, together with the disubstitution product 17. Compounds 15 and 16 were shown to be intermediates in the formation of 17.

Triflic Acid Promoted Decarboxylation of Adamantane-oxazolidine-2-one: Access to Chiral Amines and Heterocycles

“…These derivatives can be used for highly useful coupling 20 and substitution reactions. 21 For their synthesis, corresponding salts were used as precursors toward generating water-free halic acids. The 1-iodo, bromo, and chloro derivatives were prepared following the same protocol (Scheme 2).…”

Reactions of 1-haloadamantanes and ethylmercury chloride with nitronate anions by the SRN1 mechanism

“…It was suggested that 1-AdOH is formed by a polar bromophilic type mechanism within a solvent cage reaction to furnish the observed product. 8 However, in liquid ammonia this bromophilic reaction did not occur, and 1-AdBr reacted with 1 under photostimulation in the presence of acetone enolate anion to give the substitution product 2 in 75% yield [eqn. ( 6), Table 1, experiments 1 and 2…”

“…5 In order to synthesize adamantylnitromethanes in good yields we decided to investigate the reaction of 1-bromo-, 2-bromo-, 1,3-dibromo-and 1,4-dibromoadamantanes with nitromethane ions in DMSO and in liquid ammonia. 8 The photostimulated reaction of 1-AdX (X = Br, I) or 2-AdBr with nitromethane ions gave good yields of the substitution product 1-AdCH 2 NO 2 or 2-AdCH 2 NO 2 9 , respectively, in the presence of the enolate anions of acetone (entrainment conditions) in liquid ammonia. Although these reactions can be useful for preparing other nitroadamantyl derivates, a more thorough study is necessary so as to determine the scope of these reactions.…”

“…13 C-NMR (DCCl 3 ) d: 13.74, 22.13, 26.54, 28.24, 28.62, 35.90, 36.60, 38.51, 99.26. MS (EI+) m/z (%): 204 (2), 136 (11), 135 (100), 107 (6), 93 (12), 91 (9), 79 (16), 67 (8), 55 (4), 41 (6). HRMS (EI) exact mass calcd for C 15 H 25 NO 2 : 251.1885, found 251.1878.…”

About the Inhibition of Grignard Reagent Formation by p‐Dinitrobenzene: Comparing the Mechanism of Grignard Reagent Formation and the SRN1 Mechanism

“…[30] 2) Quenching of the reaction by trace amounts of oxidising agents (e.g., p-dinitrobenzene, CuCl 2 ) or radical traps (e.g., di-tert-butyl nitroxide). [26,[31][32][33][34] 3) Entrainment of the reaction: [25,[35][36][37] for example, the anion of MeNO 2 does not react with 1-iodoadamantane under irradiation, but excellent yields of 1-adamantylnitromethane are obtained in the photostimulated reaction in Scheme 1. Extending this scheme to the formation of a Grignard reagent, the role of donor would be played by the active sites of the magnesium metallic surface (see text).…”