Rh‐oad: A rhodium/diene‐catalyzed addition of sodium tetraarylborates to alkyne‐tethered 2‐cycloalken‐1‐ones has been developed for the synthesis of spirocarbocycles. The tetraarylborates catalytically form two new carbon–carbon bonds. A chiral diene ligand also asymmetrically creates quaternary spirocarbon stereocenters with high enantiomeric purity.