Abstract : The first approach to pyrazole containing helicenes via sydnone-aryne [3+2]-cycloaddition is described. An unprecedented regioselectivity in the cycloaddition step towards the more sterically constrained product was observed in presence of extended aromatic scaffolds. DFT calculations enabled to understand the origin of this unexpected selectivity.
Expédite Yen-Pon, Pier Alexandre Champagne, Lucie Plougastel, Sandra Gabillet, Pierre Thuéry, et al.. Sydnone-based Approach to Hetero-helicenes Through 1,3-Dipolar-Cycloadditions. Journal of the American Chemical Society, American Chemical Society, 2019, 141, pp.1435-1440. ⟨https://doi.org/10.1021/jacs.8b11465⟩. ⟨cea-01976854⟩
