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51.
R. G. Kostyanovsky Yu. I. El'natanov I. I. Chervin S. V. Konovalikhin A. B. Zolotoi L. O. Atovmyan 《Russian Chemical Bulletin》1996,45(7):1707-1710
The title adduct (1) was synthesized, and its conformationally and configurationally rigid chiral structure in solution and in the crystal was established by NMR spectroscopy and by X-ray structural analysis. Atropoenantiomers of1 were observed by the1H NMR method in the presence of a chiral shift reagent. A barrier to their interconversïon was determined, Gx > Z5 kcal mol–1 (200 °C).Translated fromItvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1796–1799, July, 1996. 相似文献
52.
A. V. Prosyanik V. V. Rozhkov A. S. Moskalenko A. I. Mishchenko A. Forni I. Moretti G. Torre S. Brukner L. Malpezzi R. G. Kostyanovsky 《Russian Chemical Bulletin》1998,47(1):115-118
The possibility of tranferring chirality from nitrogen to carbon by a three-step transformation of racemic dimethyl 1-methoxyaziridine-2,2-dicarboxylate into 3-amino-2-chloromethyl-2-methoxyaminopropan-1-ol was demonstrated. The first representative of 1-silyloxyaziridines,viz., dimethyl 1-(tert-butyldimethylsilyloxy)aziridine-2,2-dicarboxylate, was synthesized by acidolysis or thermolysis of triazoline, obtained by the reaction oftert-butyldimethylsilyloxime of dimethy mesoxalate with CH2N2 相似文献
53.
Comparative investigations of the mass spectra of eEH2, Me2EH, Et2EH(E = N, P); Me3E, Et3E(E = N, P, As, Sb, Bi). (n-Pr)3E(E = Sb, Bi); (n-Bu)3E(E = P, As); (n-C5H11)3As and (n-C6H13)3As as well as Et2AsBr have been carried out. Deuteroanalogues, metastable transitions and low voltage spectra were used for elucidation of the fragmentation paths. The mass spectra of MeN(CH2)2 and CD3N(CH2)2 were studied to analyse the structure of the fragments. The main degradation path of amines, i.e. α-cleavage, was shown to be untypical for P, As, Sb and Bi derivatives. 相似文献
54.
Remir G. Kostyanovsky Vladimir F. Rudchenko Vasilii G. Shtamburg Ivan I. Chervin Shahin S. Nasibov 《Tetrahedron》1981,37(24):4245-4254
Alkoxyamines with tertiary N-alkyl substituents were chlorinated to N-chloro-N-alkoxyamines whose reaction with alcohols enabled synthesis of N,N-dialkoxyamines. The DNMR method was used to determine the barriers of inversion of these compounds. Alkaline hydrolysis (13) followed by subsequent reactions with R-(+)- and S-(?)-α-phenylethylamine yielded diastereomeric salts (+29 and ?29) whose crystallization and subsequent esterification resulted in optically active acyclic amines (?13 and +13) with the asymmetric center only at the N atom in the open chain. 相似文献
55.
R. G. Kostyanovsky V. G. Plekhanov Yu. I. Elnatanov L. M. Zagurskaya V. N. Voznesensky 《Journal of mass spectrometry : JMS》1972,6(11):1199-1206
The behaviour of compounds I to XII under electron-impact (electron voltages 30 and 12 eV) was investigated. The abundance of the ions characteristic of amines was shown to decrease drastically with an increase of chain branching in alkylphosphines. Comparison of the spectra of VII and X led to the conclusion that the unshared electron pair of phosphorus does not affect the fragmentation. The main peaks in the spectra of phosphines corresponded to hydrocarbon fragments. The origins of the main fragment ions were confirmed by metastable peaks. 相似文献
56.
57.
R. G. Kostyanovsky G. K. Kadorkina O. N. Krutius I. I. Chervin 《Chemistry of Heterocyclic Compounds》2012,48(6):869-874
Diastereoselective transformations of Leakadine were discovered: dimerization during melting or heating in CHCl3 with the formation of one diastereomer. The obtained dimer reacts with methyl isocyanate under mild conditions with the formation of an N-methylcarbamoyl derivative – also in the form of one diastereomer. In the diastereoselective reaction of Leakadine with dimethyl formamide dimethyl acetal, 2-dimethylamino-1,3-diazabicyclo[3.1.0]hexan-4-one was obtained. The reaction of Leakadine with perfluoroisobutylene was studied. 相似文献
58.
P. CsöRGő A. Drápal 《Abhandlungen aus dem Mathematischen Seminar der Universit?t Hamburg》2006,76(1):17-34
A loopQ is said to be left conjugacy closed (LCC) if the left translations form a set of permutations that is closed under conjugation. This papers investigates those LCC loops where the group generated by left translations is normal in the group generated by both left and right translations. 相似文献
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