Abstract
Selected developments in the chemistry of heteroaromatic N-oxides since 2001 are presented in this review. The use of these N-oxides, both in late-transition-metal-catalyzed oxidations of carbon–carbon triple
bonds and in regioselective C–H functionalizations of the heteroarene, are contemporary
topics of interest and the focus of the discussion.
1 Introduction
2 Synthesis of Heteroaromatic N-Oxides
2.1 Direct Oxidation of Hindered Heteroarenes
2.2 Through Construction of Heteroaromatic Rings
3 Heteroaromatic N-Oxides as Oxidants
3.1 Alkyne Oxidation
3.2 Allene Oxidation
3.3 Carbene Oxidation
4 Heteroaromatic N-Oxides as Substrates
4.1 Deoxygenative ortho-C–H Functionalization with Prior Activation
4.2 Deoxygenative ortho-C–H Functionalization with Nonstabilized Carbanions
4.3 Nondeoxygenative C–H Functionalization
4.3.1 ortho-C–H Functionalization
4.3.2 N-Oxide Directed ortho-Alkyl C–H Functionalization
4.3.3 N-Oxide Directed Remote C–H Functionalization
4.4 1,3-Dipolar Cycloaddition
5 Conclusion and Outlook
Key words
oxidations - alkynes - cycloadditions - carbenes - pyridines
