This report describes an investigation into the effect that proximal functionality has on the allylic azide equilibrium. We report 16 allylic azides with varied functionality from three subclasses. We observe a correlation of % branched azide to the pKa of the OR group. We also observe that RN–H azides have a higher % branched azide relative the corresponding RN–Bn compound. These two effects combine to describe the observed equilibrium for the known compound hydroxy-crotyl azide. DFT calculations support several stereoelectronic effects that contribute to the relative energetics.
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We are grateful for helpful discussions with Grace Gast and Prof. Steve Kass. We gratefully acknowledge the University of Minnesota and the American Chemical Society's Petroleum Research Fund (PRF # 56505-DNI1) for financial support. The Minnesota Supercomputing Institute (MSI) at the University of Minnesota provided resources that contributed to the results reported within this paper.
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