<i>Endo</i>-selective [2+2] cycloaddition of norbornadienes enables the synthesis of homocubanes

Article excerpt

Nature Chemistry, Published online: 10 July 2026; doi:10.1038/s41557-026-02201-x The [2+2] cycloaddition of norbornadienes and alkynes usually favours the formation of the exo adducts. Now, a nickel-catalysed endo-selective [2+2] cycloaddition has been developed, which has been used to generate otherwise elusive endo-tricyclononadienes, and further derivatized via intramolecular [2+2] photocycloaddition to synthesize homocubanes.