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71.
72.
Formation of N‐sulfonylaziridines, N‐ethylidenesulfonamides, N‐vinylsulfonamides and 4,5‐dihydro‐1,2,3‐oxathiazole 2‐oxides by the reaction of singlet and triplet trifluoromethyl‐, methyl‐ and tosylnitrenes with ethylene is studied computationally at the B3LYP/6‐311++G(d,p) level of theory in both gas phase and in solution. Singlet sulfonylnitrenes react with ethylene via [1 + 2]‐cycloaddition exothermically to give N‐sulfonylaziridines. Triplet sulfonylnitrenes are formed from the singlet ones by the intersystem crossing with the energy barrier not exceeding 2.5 kcal/mol and react in a stepwise fashion by C‐addition or H‐abstraction. The C‐addition gives rise to the formation of N‐sulfonylaziridines or N‐ethylidenesulfonamides depending on the S―N―Csp3―Csp2 dihedral angle, with the barrier to rotation about the N―Csp3 bond not exceeding 2.5 kcal/mol. The H‐abstraction results in N‐vinylsulfonamides. Transformation of N‐sulfonylaziridines to N‐ethylidenesulfonamides requires to overcome the barrier of 57–60 kcal/mol, N‐ethylidenesulfonamides to 4,5‐dihydro‐1,2,3‐oxathiazole 2‐oxides—74–80 kcal/mol and N‐vinylsulfonamides to N‐ethylidenesulfonamides—about 64 kcal/mol. The use of the polarizable continuum model does not lead to a change of the course of the reaction of trifluoromethanesulfonylnitrene with ethylene and only slightly affects the relative energies of the products, intermediates and transition states. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
73.
In order to synthesize the first seven-membered N-triflylazasilacycloalkane the reaction of triflamide with (2-bromoethyl)(3-chloropropyl)dimethylsilane was studied. Depending on the reaction conditions bis(3-chloropropyl)tetramethyldisiloxane, 3-trifluoromethylsulfonylaminopropyl(3-chloropropyl)-tetramethyldisiloxane, (2-triflamidoethyl)(3-chloropropyl)dimethylsilane, bis(3-triflamidopropyl)tetramethyldisiloxane, and the target 4,4-dimethyl-1-(trifluoromethylsulfonyl)-1,4-azasilepane have been isolated. In all cases the halogen atom in the β-bromoethyl group is replaced first. Low-temperature 1H NMR spectroscopy showed that the prepared seven-membered heterocycle is conformationally flexible. 相似文献
74.
1,5-Hexadiene reacts with trifluoromethanesulfonamide in the oxidative system (t-BuOCl+NaI) to give trans-2,5-bis(iodomethyl)-1-(trifluoromethylsulfonyl)pyrrolidine 5 and 3,8-bis(trifluoromethylsulfonyl)-3,8-diazabicyclo[3.2.1]octane 6. With arenesulfonamides ArSO2NH2 (Ar=Ph, Tol), the reaction stops at the formation of the trans and cis isomers of 2,5-bis(iodomethyl)-1-(arenesulfonyl)pyrrolidine 7 and 8 (1:1). The cis isomers of 7 and 8 do not undergo cyclization to the corresponding 3,8-disubstituted 3,8-diazabicyclo[3.2.1]octanes. The reaction with triflamide represents the first example of one-pot two-step route to 3,8-diazabicyclo[3.2.1]octane system. 相似文献
75.
Mikhail Yu. Moskalik Vera V. Astakhova Uwe Schilde Irina V. Sterkhova Bagrat A. Shainyan 《Tetrahedron》2014
Reaction of trifluoromethanesulfonamide (triflamide) CF3SO2NH2 with 2,3-dimethylbuta-1,3-diene (2) and 2,5-dimethylhexa-2,4-diene (3) in the oxidative system (t-BuOCl+NaI) results in the formation of 2,4-dimethyl- or 2,2,4,4-tetramethyl-3,6-bis(triflyl)diazabicyclo[3.1.0]hexane through two successive heterocyclizations. Reaction of diene (3) with arenesulfonamides ArSO2NH2 (Ar=Ph, Tol), stops at the formation of the product of oxidative 1,4-addition, N,N′-(2,3-dimethylbut-2-ene-1,4-diyl)diarenesulfonamides, providing evidence of the essential difference between the reactivity of triflamide and arenesulfonamides. 相似文献
76.
In the search for an approach to N-vinyltriflamides with a free NH group TfNHCH=CHR (Tf = CF3SO2) N-(benzyl)-N-(2-bromo-2-phenylethenyl)triflamide TfN(Bn)CH=CHPh was synthesized through bromination-dehydrobromination of N-(benzyl)-N-(2-phenylethyl)triflamide. At removing the benzyl protecttion by the action of trifluoromethanesulfonic acid benzyl alcohol separated; however instead of the target N-styryltriflamide unexpectedly the product of its hydrogenation was obtained, N-(2-phenylethyl)triflamide. Obviously, the benzyl alcohol was the hydrogen donor, and the easy hydrogenation was facilitated by the high electrophilicity of the double bond in N-styryltriflamide because of strong electron-acceptor effect of the triflyl group. 相似文献
77.
N. N. Chipanina T. N. Aksamentova L. V. Sherstyannikova I. V. Sterkhova B. A. Shainyan V. K. Turchaninov 《Russian Journal of Organic Chemistry》2005,41(10):1415-1420
According to the data of IR spectroscopy, dielcometry, and B3LYP/6-31G* quantum-chemical calculations, trifluoromethanesulfonamide homoassociates in weakly basic protophilic media are converted into 2 : 1 solvate H-complexes. Cyclic trifluoromethanesulfonamide dimer decomposes in heteroassociate with dioxane with a composition of 1 : 3. Cyclic trifluoromethanesulfonamide dimer with dioxane forms a 1 : 4 H-complex with bifurcated (three-center) hydrogen bond involving the bridging hydrogen atom of the NH group (NH?O). 相似文献
78.
Grigor'eva A. A. Shainyan B. A. Kaurova G. I. Gracheva E. I. Lesnevskaya N. B. Barabanov V. G. 《Russian Journal of Applied Chemistry》2002,75(7):1095-1100
Electrochemical fluorination of some unsaturated sulfides and sulfones and their reactions with anhydrous HF were studied. 相似文献
79.
The stereodynamic behaviour of 1-(trifluoromethylsulfonyl)piperidine 1, 4-(trifluoromethylsulfonyl)morpholine 2, 1,4-bis(trifluoromethylsulfonyl)piperazine 3 and 4-(trifluoromethylsulfonyl)thiomorpholine 1,1-dioxide 4 was studied by low-temperature 1H, 13C and 19F NMR spectroscopies. In acetone solution, compounds 1, 2 and 4 were found to exist as mixtures of two conformers in the ratio of 4:1, 4:1 and 8:1, respectively, differing by orientation of the CF3 group with respect to the ring. Compound 3 exists as a mixture of three conformers in the ratio of 3:28:69 also differing by the orientation of the two CF3 groups. Unlike the previously studied N-trifyl substituted 1,3,5-triheterocyclohexanes, the preferred conformers of compound 1 and of 1,4-diheterocyclohexanes 2-4 are those with the CF3 group directed outward from the ring, which is caused by intramolecular interactions of the oxygen atoms of the CF3SO2N groups with the equatorial hydrogens in the α-position. B3LYP/6-311+G(d,p) calculations of the energy, geometry and NMR parameters corroborate the experimental data. The calculated Perlin effects for all conformers of compounds 1-4 as well as those measured for the major conformers of compounds 3 and 4 were analyzed by the use of the NBO analysis. 相似文献
80.
Bagrat A. Shainyan Nina N. Chipanina Larisa P. Oznobikhina Vladimir I. Meshcheryakov 《Journal of Physical Organic Chemistry》2016,29(2):92-100
The effect of the electron–acceptor substituent CF3SO2 at the imine nitrogen atom on the basicity and the electron distribution in N,N‐alkylformamidines ( 1 , 2 , 3 , 4 , 5 ) was studied experimentally by the FTIR spectroscopy and theoretically at the DFT (B3LYP/6‐311+G(d,p)) level of theory, including the natural bond orbital (NBO) analysis. The calculated proton affinities of the imine nitrogen atom and the sulfonyl oxygen (PAN′ and PAO) depend on the atomic charges, the C?N′ and N′―S bond polarity and on the energy of interaction of the amine nitrogen and the oxygen lone pairs with antibonding π* and σ*‐orbitals. The basicity of the imine nitrogen atom is increased with the increase of the electron‐donating power of the substituent at the amine nitrogen atom due to stronger interaction nN → π*C?N′, but is decreased for the electron‐withdrawing groups MeSO2 and CF3SO2 at the imine nitrogen atom in spite of the increase of this conjugation. Protonation of ( 1 , 2 , 3 , 4 , 5 ) in CH2Cl2 solution in the presence of CF3SO3H occurs at the imine nitrogen atom, while the formation of hydrogen bonds with 4‐fluorophenol takes place at the sulfonyl oxygen atom, whose basicity is lower than that of N,N′‐dimethylmethanesulfonamide but higher than of N,N′‐dimethyltrifluoromethanesulfonamide. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献