title: Catalytic asymmetric construction of 3,3'-spirooxindoles fused with seven-membered rings by enantioselective tandem reactions.
abstract: The first catalytic asymmetric construction of a spirooxindole scaffold incorporated with a seven-membered benzodiazepine moiety has been established by a three-component (isatin, 1,2-phenylenediamine, cyclohexane-1,3-dione) tandem reaction catalyzed by a chiral phosphoric acid. Structurally complex spirobenzodiazepine oxindoles with one quaternary stereogenic center are obtained in high yield with excellent enantioselectivity (up to 99% yield, enantiomeric ratio>99.5:0.5). This approach takes advantage of organocatalytic asymmetric tandem reactions to efficiently construct the structurally rigid spirobenzodiazepine oxindole architecture with high enantiopurity in a single transformation, which involves a cascade enamine-imine formation/intramolecular Mannich reaction sequence.
authors.affiliation: School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116 (P. R. China), Fax: (+86) 516-83500065.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Shi
authors.forename: Xi-Xi
authors.initials: XX
authors.lastname: Yao
authors.forename: Meng
authors.initials: M
authors.lastname: Sun
authors.forename: Liang
authors.initials: L
authors.lastname: Dong
authors.forename: Shu-Jiang
authors.initials: SJ
authors.lastname: Tu
mesh_terms: D001569:Benzodiazepines / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D000078183:Oxindoles; D010756:Phosphoric Acids / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D007211:Indoles; D000078183:Oxindoles; D010756:Phosphoric Acids; D013141:Spiro Compounds; C022960:2-oxindole; D001569:Benzodiazepines; C030242:phosphoric acid
keywords: asymmetric synthesis; domino reactions; enantioselectivity; organocatalysis; spiro compounds