Chiral bisguanidine-catalyzed inverse-electron-demand hetero-Diels-Alder reaction of chalcones with azlactones.
A new type of C(2)-symmetric chiral bisguanidine was designed as a highly efficient catalyst in the inverse-electron-demand hetero-Diels-Alder reaction of chalcones with azlactones for the first time. A wide variety of gamma,delta-unsaturated delta-lactone derivatives with alpha-quaternary-beta-tertiary stereocenters were obtained in high yields (up to 88%) with excellent enantioselectivities (up to 99% ee). Hydrogen bonds were considered to be crucial for the activation and stereoinduction of the reaction. In all cases, the major was HDA adducts, which were obtained as a single diastereomer along with little amount of Michael addition products.
Dong
Shunxi
S
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China.
Liu
Xiaohua
X
Chen
Xiaohong
X
Mei
Fang
F
Zhang
Yulong
Y
Gao
Bo
B
Lin
Lili
L
Feng
Xiaoming
X
D001372:Aza Compounds / Q000737:chemistry*; D002384:Catalysis; D047188:Chalcones / Q000737:chemistry*; D004583:Electrons; D006146:Guanidines / Q000737:chemistry*; D006860:Hydrogen Bonding; D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
D001372:Aza Compounds; D047188:Chalcones; D006146:Guanidines; D007783:Lactones