Novel synthesis of α-nitroalkenes from nitroalkanes via halogenation of intermediate N,N-bis(silyloxy)enamines
An approach to conjugated nitroalkenes via oxidation of N,N-bis(silyloxy)enamines with bromine or iodine in the presence of tetra-n-butylammonium acetate is described. The acetate ion plays a key role by acting as a mild desilylating reagent. This new strategy allows the synthesis of α-nitroalkenes from the corresponding nitroalkanes.
Kunetsky, Roman A.,Dilman, Alexander D.,Struchkova, Marina I.,Tartakovsky, Vladimir A.,Ioffe, Sema L.
p. 5203 - 5205
(2007/10/03)
Trimethylsilyl Nitronates Derived from 2-Substituted Nitroethanes in δ-Elimination Reactions
Silylation of β-substituted nitroethanes XCH2CH2NO2 (X=Cl or OCOCH3) with conventional silylating agents yields corresponding trimethylsilyl nitronates which undergo δ-elimination of nitroethylene under the reaction conditions.Stable silyl nitronates containing one or two trimethylsilyl groups were isolated in the silylation of C6H5NHCH2CH2NO2. 1,3-Dipolar cycloaddition of the nitronates to methoxide ion results in formation of 5-methoxycarbonyl-3-phenylaminomethyl(or 3-N-trimethylsilylphenylaminomethyl)-3-trimethylsiloxyisoxazolidines.Thermolysis of the latter affords 5-methoxycarbonyl-2-isoxazoline.
Ioffe, S. L.,Makarenkova, L. M.,Strelenko, Yu. A.,Tartakovskii, V. A.