Rh-catalyzed dynamic kinetic intramolecular [4+2] cycloaddition reaction of 1,3-disubstituted allene-1,3-dienes afforded cis-fused [4.3.0]bicyclic products with an excellent chemo-, diastereo-, and enantio-selectivity. Many synthetically useful functional groups are tolerated. The synthetic utility has been demonstrated. Based on the careful experimental studies, a mechanism involving the rapid racemization of the allene moiety in the starting materials has been proposed.

    We have made continous efforts on intramolecular [4+2] cycloaddition reaction of allene-dienes. For the racemic version, see Org. Chem. Front. 2018, 5, 2680.; For the asymmetric version via chirality transfer approach, see Chin. J. Chem. 2019, 37, 486.; For the asymmetric version via kinetic resolution, see Chin. J. Chem. 2021, 39, 559 (Breaking Report). Now the dynamic kinetic approach has been realized!