title: Enantioselective 1,3-dipolar cycloaddition of methyleneindolinones and N,N'-cyclic azomethine imines.
abstract: A new chiral bis-phosphoric acid 3l bearing triple axial chirality was synthesized and applied to effect a highly enantioselective 1,3-dipolar cycloaddition reaction between N,N'-azomethine imines and methyleneindolinones for the creation of chiral spiro[pyrazolidin-3,30-oxindoles] in excellent yields and selectivities. MS experiment and DFT calculation studies prompted us to propose a dual H-bond donor activation mode of bis-phosphoric acid which is different from the traditional phosphoric acid catalysis.
authors.affiliation: Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, PR China. hongl@lzu.edu.cn
authors.forename: Liang
authors.initials: L
authors.lastname: Hong
authors.forename: Ming
authors.initials: M
authors.lastname: Kai
authors.forename: Chongyang
authors.initials: C
authors.lastname: Wu
authors.forename: Wangsheng
authors.initials: W
authors.lastname: Sun
authors.forename: Gongming
authors.initials: G
authors.lastname: Zhu
authors.forename: Guofeng
authors.initials: G
authors.lastname: Li
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Yao
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D003500:Cyclization; D007097:Imines / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D008745:Methylation; D008958:Models, Molecular; D000078183:Oxindoles; D013237:Stereoisomerism; D013882:Thiosemicarbazones / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D007097:Imines; D007211:Indoles; D000078183:Oxindoles; D013882:Thiosemicarbazones; C512188:azomethine; C022960:2-oxindole