A Catalytic Asymmetric Ring‐Expansion Reaction of Isatins and α‐Alkyl‐α‐Diazoesters: Highly Efficient Synthesis of Functionalized 2‐Quinolone Derivatives

• DOI: 10.1002/anie.201204594
• Publication Date: 2012-07-23T06:45:39Z
• Authors: Wei Li; Xiaohua Liu; Xiaoyu Hao; Yunfei Cai; Lili Lin; Xiaoming Feng
• Keywords: Stereocenter; Quinolone

Asymmetric expansion: A catalytic asymmetric ring-expansion reaction of the title compounds occurs in presence a Sc(OTf)(3) catalyst bearing an N,N'-dioxide-based ligand. Highly functionalized 2-quinolone derivatives containing chiral C4-quaternary stereocenter were obtained high yields and levels selectivity under mild conditions (see scheme; Tf=trifluoromethanesulfonyl).