title: Organocatalytic Enantioselective Formal [4 + 2] Cycloaddition of Enones with Cyclic N-Sulfonylimines and Methylene Chromene for Chiral Spirocyclic Compounds.
abstract: A highly enantioselective synthesis of spirocycles and bridged rings has been developed through a formal [4 + 2] cycloaddition reaction between enones and N-sulfonylimines. The unprecedented strategy has been realized utilizing N-sulfonylimine as a novel dienophile through enamine-iminium tautomerism of N-sulfonylimine. In addition, a γ,ε-regioselective cycloaddition reaction proceeded by employing methylene chromene species as dienophiles.
authors.affiliation: Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Fei
authors.affiliation: Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Qian
authors.affiliation: Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Sun
authors.affiliation: Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Gu
authors.affiliation: Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, China.
authors.forename: Chuncheng
authors.initials: C
authors.lastname: Zou
authors.affiliation: Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology , 130 Meilong Road, Shanghai 200237, China.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Ye