Catalytic endo-stereoselective... Note

Catalytic endo-stereoselective [2+2] cycloaddition of norbornadienes with internal alkynes

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-tricyclononadienes and substituted homocubanes.