1. Reaction of β -Nitrostyrene with Diethyl Malonate in the Presence of Bispidines: The Unusual Role of the Organocatalyst.
- Author
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Dalinger, Alexander I., Mamedova, Sabina F., Burykina, Julia V., Pentsak, Evgeniy O., and Vatsadze, Sergey Z.
- Subjects
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ELECTROSPRAY ionization mass spectrometry , *THERMOGRAVIMETRY , *NUCLEAR magnetic resonance spectroscopy , *ELEMENTAL analysis , *SCANNING electron microscopy , *OLIGOMERS , *NITROALDOL reactions - Abstract
The aim of this work was the investigation of novel organocatalysts for the Michael addition of diethyl malonate to β-nitrostyrene. The methodology of the study included NMR titration, reaction monitoring by NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS), product characterization by MALDI, IR spectroscopy, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and elemental analysis. As a result, evidence of supramolecular interactions between two pairs of components of the reaction was found. In addition to the supramolecular complexes, an unusual reaction, i.e., the Michael addition of NH-bispidines to β-nitrostyrene, was found, which led to previously unknown oligomers of β-nitrostyrene. A new mechanism for the catalytic action of NH-bispidine was proposed, which involved catalysis not by the initial organocatalyst but rather by its adduct with β-nitrostyrene. Thus, in this reaction, N-benzylbispidine acted as an initiator, and the real catalyst was the betaine formed during the initiation stage. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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