%0 Journal Article
%A Kilaj, Ardita
%A Wang, Jia
%A Stranak, Patrik
%A Schwilk, Max
%A Rivero, Uxía
%A Xu, Lei
%A Anatole von Lilienfeld, O.
%A Küpper, Jochen
%A Willitsch, Stefan
%T Conformer-specific polar cycloaddition of dibromobutadiene with trapped propene ions
%J Nature Communications
%V 12
%N 1
%@ 2041-1723
%C [London]
%I Nature Publishing Group UK
%M PUBDB-2021-02598
%M arXiv:2107.13858
%P 6047
%D 2021
%X There has been a long-standing discussion in the literature whether Diels-Alder cy- cloadditions and their ionic variants, polar cycloadditions, proceed via stepwise or con- certed reaction mechanisms. Here, we adopt a new experimental approach to explore the mechanistic details of these reactions by probing its conformational specificities in the entrance channel using conformationally controlled molecular beams combined with ion-trapping techniques. For the model polar cycloaddition of 2,3-dibromo-1,3-butadiene with propene ions, we found that two conformers of the diene, gauche and s-trans, are reactive with capture-limited reaction rates. Aided by theoretical calculations, this find- ing is rationalised by a simultaneous competition of both concerted and stepwise reaction pathways thus revealing an interesting mechanistic borderline case. The present study illustrates the utility of experiments with controlled molecules under single-collision conditions in the gas phase for unravelling mechanistic details of reactions relevant for synthetic chemistry.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ 34663806
%U <Go to ISI:>//WOS:000708601800018
%R 10.1038/s41467-021-26309-5
%U https://bib-pubdb1.desy.de/record/459533