Glover, Stephen A

Rosser, Adam A

2018-10-31

This article was also included as a book chapter in, Amide Bond Activation, 2019 by MDPI, ISBN 9783039212033 (paperback); ISBN 9783039212040 (PDF). 10.3390/books978-3-03921-204-0

<p> This review describes how resonance in amides is greatly affected upon substitution at nitrogen by two electronegative atoms. Nitrogen becomes strongly pyramidal and resonance stabilisation, evaluated computationally, can be reduced to as little as 50% that of <i>N</i>,<i>N</i>-dimethylacetamide. However, this occurs without significant twisting about the amide bond, which is borne out both experimentally and theoretically. In certain configurations, reduced resonance and pronounced anomeric effects between heteroatom substituents are instrumental in driving the HERON (Heteroatom Rearrangement On Nitrogen) reaction, in which the more electronegative atom migrates from nitrogen to the carbonyl carbon in concert with heterolysis of the amide bond, to generate acyl derivatives and heteroatom-substituted nitrenes. In other cases the anomeric effect facilitates S_N1 and S_N2 reactivity at the amide nitrogen.</p>

Molecules, 23(11), p. 1-39

1420-3049

1431-5165

30384496

https://hdl.handle.net/1959.11/26469

MDPI AG

Attribution 4.0 International

Heteroatom Substitution at Amide Nitrogen-Resonance Reduction and HERON Reactions of Anomeric Amides

Journal Article

Publication