1. The Azide-Allene Dipolar Cycloaddition: Is DFT Able to Predict Site- and Regio-Selectivity?
- Author
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Molteni, Giorgio, Ponti, Alessandro, and Quadrelli, Paolo
- Subjects
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REGIOSELECTIVITY (Chemistry) , *RING formation (Chemistry) , *ALLENE , *FORECASTING - Abstract
The site- and regio-selectivity of thermal, uncatalysed 1,3-dipolar cycloadditions between arylazides and mono- or tetra-substituted allenes with different electronic features have been investigated by both conceptual (reactivity indices) and computational (M08-HX, ωB97X-D, and B3LYP) DFT approaches. Both approaches show that these cycloadditions follow a nonpolar one-step mechanism. The experimental site- and regio-selectivity of arylazides towards methoxycarbonyl- and sulfonyl-allenes as well as tetramethyl- and tetrafluoro-allenes was calculated by DFT transition state calculations, achieving semiquantitative agreement to both previous and novel experimental findings. From the mechanistic standpoint, 1H-NMR evidence of a methylene-1,2,3-triazoline intermediate reinforces the reliability of the computational scheme. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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