title: Asymmetric synthesis of 3,3'-spirooxindoles fused with cyclobutanes through organocatalytic formal [2 + 2] cycloadditions under H-bond-directing dienamine activation.
abstract: The first organocatalytic asymmetric synthesis of a spirooxindole skeleton incorporated with a cyclobutane moiety has been successfully developed on the basis of H-bond-directing dienamine activation. Structurally complex spirocyclobutyl oxindoles, which possess four contiguous stereocenters, including one spiro quaternary center, were obtained in good yields (up to 83%) with excellent β,γ-regioselectivity (>19:1) and stereocontrol (up to >19:1 dr and 97% ee).
authors.affiliation: Key Laboratory of Asymmetric Synthesis and Chirotechnology of Sichuan Province, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences , Chengdu 610041, China.
authors.forename: Liang-Wen
authors.initials: LW
authors.lastname: Qi
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.forename: Yong-Yuan
authors.initials: YY
authors.lastname: Gui
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Fang
authors.initials: F
authors.lastname: Tian
authors.forename: Lin
authors.initials: L
authors.lastname: Peng
authors.forename: Li-Xin
authors.initials: LX
authors.lastname: Wang
mesh_terms: D002384:Catalysis; D003500:Cyclization; D003503:Cyclobutanes / Q000138:chemical synthesis* / Q000737:chemistry; D006860:Hydrogen Bonding; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D000078183:Oxindoles; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D003503:Cyclobutanes; D007211:Indoles; D000078183:Oxindoles; D013141:Spiro Compounds; C022960:2-oxindole