TY  - JOUR
AU  - Kilaj, Ardita
AU  - Wang, Jia
AU  - Stranak, Patrik
AU  - Schwilk, Max
AU  - Rivero, Uxía
AU  - Xu, Lei
AU  - Anatole von Lilienfeld, O.
AU  - Küpper, Jochen
AU  - Willitsch, Stefan
TI  - Conformer-specific polar cycloaddition of dibromobutadiene with trapped propene ions
JO  - Nature Communications
VL  - 12
IS  - 1
SN  - 2041-1723
CY  - [London]
PB  - Nature Publishing Group UK
M1  - PUBDB-2021-02598
M1  - arXiv:2107.13858
SP  - 6047
PY  - 2021
AB  - 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.
LB  - PUB:(DE-HGF)16
C6  - 34663806
UR  - <Go to ISI:>//WOS:000708601800018
DO  - DOI:10.1038/s41467-021-26309-5
UR  - https://bib-pubdb1.desy.de/record/459533
ER  -