Reaction of N,N-Dioxyenamines with Anhydrides of Carboxylic and Sulfonic Acids; A New Method for the Synthesis of α-Hydroxyoxime Derivatives
作者:Alexey Lesiv、Andrey Tabolin、Sema Ioffe
DOI:10.1055/s-0029-1216907
日期:2009.9
The reactions of N,N-dioxyenamines with carboxylic and sulfonic acid anhydrides were investigated. A newmethod for the synthesis of α-hydroxyoxime derivatives via the reaction of N,N-dioxyenamines with trifluoroacetic anhydride is described. 1,2-oxazine - trifluoroacetic anhydride - hydroxyoxime - enamine - rearrangement
Five-Membered Cyclic Nitronates in C-C Coupling with 1-(<i>tert</i>-Butyldimethylsilyloxy)-1-methoxyethylene
作者:Vladimir O. Smirnov、Alexander S. Sidorenkov、Yulia A. Khomutova、Sema L. Ioffe、Vladimir A. Tartakovsky
DOI:10.1002/ejoc.200900172
日期:2009.6
Five-memberedcyclicnitronates 3 undergo TBSOTf-catalysed C–Ccoupling reactions with silyl ketene acetal 4 to give good to excellent yields of 3,3-disubstituted N-(OTBS)-isoxazolidines 5, which could not be obtained by previously known procedures. The problems of diastereoselectivity of the C–Ccoupling reactions are discussed. The transformations of the nitroso acetals 5 upon action of AcFOH/methanol
Thermodynamic Stability and Reactivity of Silylated Bis(oxy)iminium Ions
作者:Yulia A. Khomutova、Vladimir O. Smirnov、Herbert Mayr、Sema L. Ioffe
DOI:10.1021/jo070633x
日期:2007.11.1
trialkylsilyl triflates was investigated by applying NMR techniques. In several cases, a flexible nitronate−bis(oxy)iminium ion (as an ion pair with triflate as counterion) equlibrium was found, and its thermodynamic parameters were determined. Elevation of temperature or dilution shifts this equilibrium toward the reactants. Activation parameters for the C,C-coupling reaction of silylated bis(oxy)iminium ions
A method for the synthesis of isoxazolinesN-oxidesfrom primary aliphatic nitro compounds and olefins based on the 1,3-dipolar cycloaddition of intermediate 1-halo-substituted silyl nitronates, followed by halosilane elimination has been described. The nature of the halogen atom plays a key role in determining the stability and reactivity of all intermediates of this process. Bromonitro compounds
New Approach for the Synthesis of Isoxazoline-<i>N</i>-oxides
作者:Roman A. Kunetsky、Alexander D. Dilman、Sema L. Ioffe、Marina I. Struchkova、Yury A. Strelenko、Vladimir A. Tartakovsky
DOI:10.1021/ol0360602
日期:2003.12.1
[GRAPHICS]A strategy for the synthesis of isoxazoline-N-oxides (cyclic five-membered nitronates) from primary nitro compounds and olefins is described. The key step of the process involves 1,3-dipolar cycloaddition of corresponding 1-bromosilyl nitronates with alkenes.