The application of one- and two-dimensional NMR spectroscopy methods in the analysis of 1,3-dipolar cycloaddition reaction products of some azomethine ylides
Andrey S. Kochukov, 1, Svetlana V. Borisova, 1, Vitaly V. Sorokin, 1.
1 Saratov State University
Abstract
The present work describes the characterization of new spiropyrrolidines and determination of their structural features by one- dimensional and two-dimensional NMR methods (1H, 13C, HMBC, COSY, HSQC, NOESY-2D). Approaches to the analysis of a mixture of possible regio- and diastereoisomeric products of the reaction of 1,3-dipolar cycloaddition of azomethine ylides obtained in situ by multicomponent condensation of indenoquinoxalinone, isatin and arylideneacetylpyrroles and arylidenemalonodinitriles as dipolarophiles are proposed. Schemes for the interaction of various dipolarophiles with azomethine ylides are proposed using various spectral methods of analysis. In the course of the work done, it was found that the interaction of 1,3-dipoles and dipolarophiles leads to the production of products of a certain structure. The stereoisomeric structure of the reaction products was established from the characteristic signals and correlations in the NMR spectra of spiroindenoquinoxaline pyrrolidines. On the basis of the structures of the obtained compounds, the putative advantageous ylide shapes and favorable transition state conformations for concerted dipolar cycloaddition were confirmed.
Speaker
Kochukov A. S.
Saratov State University
Russia
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