Peculiarities of chemical properties of imidazole-derived and other types of cyclic nitrones and their use in Organic Synthesis
Igor A. Grigor’ev
N.N.Vorozhtsov Institute of Organic Chemistry Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
E-mail: grig@nioch.nsc.ru
Dedicated to Prof. Alexander F. Pozharskii on the occasion of his 70th birthday
Abstract
Nitrones are still of special interest for researchers both due to a broad spectrum of their application in various spheres of knowledge and their successful use as building blocks in different synthetic strategies. In this connection, the width of their application range makes the search for novel synthetic approaches to nitrones and their chemical transformation an urgent task. Reactivity of nitrones largely depends on their configuration and cyclic nitrones with E- configuration are more likely to be chemically modified rather than their acyclic analogues, which allows us to apply new approaches to functional heterocyclic compounds due to the reaction capacity of the nitrone group included into their structure. First of all it concerns the reactions with electrophilic and nucleophilic reagents. Besides, there have been found new methods of nitrone group activation both with nucleophilic reagents by radical cation formation and with electrophilic reagents by generating dipolar-stabilized anions. Electronic structure of active intermediate particles has been studied and a possible explanation for the differences in reactivity of cyclic and acyclic nitrones has been given.
Keywords: Complex induced proximity effect, cyclic voltammogram, dipolar-stabilized anion, electrochemical oxidation, metalation, NMR spectra, nitrone, radical cation
Table of Contents
1. Electrophilic Reactions of Cyclic Nitrones
1.1. Reactions of electrophilic substitution of •-alkyl nitrones
1.2. Nitration of •-aryl nitrones
1.3. Electrophilic substitution at •-carbon atom
1.3.1. Metalation of nitrones
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