Enantioselective Copper-Catalyzed Formal [4 + 2] Cycloaddition of <i>o</i>-Aminophenol Derivatives with Propargylic Esters for Synthesis of Optically Active 3,4-Dihydro-2<i>H</i>-1,4-benzoxazines
作者:Zhen-Ting Liu、Ya-Hui Wang、Fu-Lin Zhu、Xiang-Ping Hu
DOI:10.1021/acs.orglett.6b00322
日期:2016.3.4
The first copper-catalyzed asymmetric formal [4 + 2] cycloaddition of o-aminophenol derivatives with propargylic esters as the bis-electrophilic C2 synthons for the stereoselective construction of chiral 2,3,4-trisubstituted 2H-1,4-benzoxazines bearing an exocyclic double bond has been developed. By using a structurally modified chiral ketimine P,N,N-ligand, a wide range of optically active 2H-1,4-benzoxazines
首次铜催化邻氨基苯酚衍生物与炔丙酸酯作为双亲电子C2合成子的不对称[4 + 2]环加成,用于立体选择性地构建手性2,3,4-三取代的2 H -1,4-苯并恶嗪轴承已经开发了环外双键。通过使用结构改性的手性酮亚胺P,N,N-配体,可以高收率和极好的对映选择性(高达97%ee)制备各种光学活性的2 H -1,4-苯并恶嗪。