A Catalytic Asymmetric Ring‐Expansion Reaction of Isatins and α‐Alkyl‐α‐Diazoesters: Highly Efficient Synthesis of Functionalized 2‐Quinolone Derivatives
作者:Wei Li、Xiaohua Liu、Xiaoyu Hao、Yunfei Cai、Lili Lin、Xiaoming Feng
DOI:10.1002/anie.201204594
日期:2012.8.20
Asymmetric expansion: A catalytic asymmetric ring‐expansion reaction of the title compounds occurs in the presence of a Sc(OTf)3 catalyst bearing an N,N′‐dioxide‐based ligand. Highly functionalized 2‐quinolone derivatives containing a chiral C4‐quaternary stereocenter were obtained in high yields and high levels of selectivity under mild reaction conditions (see scheme; Tf=trifluoromethanesulfonyl)
非对称扩展:标题化合物的催化非对称扩环反应发生在钪(OTF)的存在3催化剂承载有Ñ,Ñ '基于二氧化物-配体。以高产率和温和的反应条件下高水平选择性的得到含有手性C4季立体中心高度官能2-喹诺酮衍生物(参见方案; TF =三氟甲磺酰基)。