Indole Synthesis and Beyond

by Tohru Fukuyama
Graduate School of Pharmaceutical Sciences
University of Tokyo

pyridine N-oxide

Recent trends in the chemistry of pyridine N-oxide Shaker Youssif Department of Chemistry, Faculty of Science, Zagazig University, Zagazig, Egypt Abstract This review describes the synthesis and reactions of pyridine N-oxides within the last ten years. The first part survyes the different synthetic methods which include ring transformation, classical oxidations using peracids, the use of metalloorganic oxidizing agents and cycloaddition reactions. The second part survys the reactions of pyridine N-oxides including the deoxygenation, nucleophillic reaction and cycloaddition to N-O BOND
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Key words: Pyridine N-oxides
Introduction Spectroscopic properties
1 Synthesis of pyridine N-oxides
1.1 From the esters of N-hydroxy-2-thiopyridone
1.2 By ring transformation of isooxazoles.
1.3. By the oxidation of pyridine derivatives
1.3.1 Using H2O2/ AcOH
1.3.2 Using H2O2/ manganese tetrakis(2,6-dichlorophenyl)porphyrin
1.3.3 Using H2O2/ methyltrioxorhenium (MTO)
1.3.4 Using dimethyldioxirane (DMD)
1.3.5 Using bis(trimethylsilyl)peroxide (BTSP)
1.3.6 Using Caro’s acid
1.3.7 Using m-chloroperoxybenzoic acid
1.3.8 Using oxaziridines
1.4 Through cycloaddition reaction
2 Reactions of pyridine N-oxides
2.1 Deoxygenation
2.2 Rearrangement of allyloxypyridine N-oxide
2.3 Nucleophilic reactions
2.4 Metallation followed by electrophilic substitution
2.5 O- Alkylation.
2.6 Nucleophilic substitution of 3-bromo-4-nitropyridine N-oxide.
2.7 Cycloaddition to dipolar N-O
3 Conclusion