Rhodium-Catalyzed Asymmetric Synthesis of Spirocarbocycles

Significance

Enantiomerically pure spirocycles with a quaternary spirocarbon stereocenter are found in natural products, biologically active compounds, and chiral ligands for asymmetric catalysis. The authors report an asymmetric rhodium-catalyzed addition of sodium tetraarylborates 2 to alkyne-tethered 2-cycloalken-1-ones 1 for the construction of the spirocyclic product 3 via an arylrhodation-1,4-rhodium migration sequence. Good yield and excellent ee values can be obtained using the chiral diene ligand (R,R)-Bn-bod*.