[3,3]-Sigmatropic Shifts of N-Allylhydrazones: Quantum Chemical Comparison of Concerted and Radical Cation Pathways

Abstract

Allylhydrazones are reported to undergo an elaborate [3,3]-sigmatropic shift/N2 extrusion sequence. Both concerted and radical cation pathways for the [3,3]-sigmatropic shift of several N-allylhydrazones were investigated using B3LYP/6-31+G(d,p) calculations. It was discovered that, assuming facile formation of the N-allylhydrazone radical cation, the rearrangement takes place through a series of low barrier steps energetically preferred to the concerted alternative available to neutral N-allylhydrazones. Subsequent N2 extrusions forming corresponding homoallyl radicals were found to be extremely facile.

Department(s)

Chemistry and Biochemistry

Document Type

Article

DOI

https://doi.org/10.1021/ol801107j

Keywords

chemical structure, energy, rearrangement, cations, extrusion

Publication Date

2008

Journal Title

Organic letters

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