Nature Chemistry, Published online: 05 June 2026; doi:10.1038/s41557-026-02167-w The endo-facial stereoselective transformation of norbornadiene (NBD) remains underdeveloped. Now a nickel(0)-catalysed endo-selective [2+2] cycloaddition of NBDs with unactivated internal alkynes is reported, enabled by ligand-mediated facial differentiation of NBDs and nickel-controlled configuration of a key intermediate. This scalable method provides an expedient route to synthetically useful endo-tricyclononadi