title: Enantioselective Copper-Catalyzed Formal [4 + 2] Cycloaddition of o-Aminophenol Derivatives with Propargylic Esters for Synthesis of Optically Active 3,4-Dihydro-2H-1,4-benzoxazines.
abstract: 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 were prepared in high yields and with excellent enantioselectivities (up to 97% ee).
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China.|University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Zhen-Ting
authors.initials: ZT
authors.lastname: Liu
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China.
authors.forename: Ya-Hui
authors.initials: YH
authors.lastname: Wang
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China.|University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Fu-Lin
authors.initials: FL
authors.lastname: Zhu
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China.
authors.forename: Xiang-Ping
authors.initials: XP
authors.lastname: Hu