Scandium-Catalyzed Asymmetric Insertion of Aryldiazomethanes

Significance

Asymmetric α-arylation of ketones can prove to be a challenge, and multistep sequences featuring asymmetric protonation are often necessary to access compounds such as 3. The authors offer an asymmetric synthesis of such α-aryl ketones through a C-C insertion of aryldiazo-methane under scandium-tris(oxazoline) ligand catalysis. The method is best suited for the synthesis of medium-sized rings, giving products in high yields and enantiomeric ratios. A model for enantioselectivity and an NMR-based proof of ­absolute configuration is provided.