title: Enantioselective construction of multifunctionalized spirocyclohexaneoxindoles through organocatalytic Michael-Aldol cyclization of isatin derived alkenes with linear dialdehydes.
abstract: Optically active spirocyclohexaneoxindole motifs are very important building blocks for preparations of biologically active complexes, natural products, and pharmaceutical compounds. Herein, we report the syntheses of enantiopure spirocyclohexaneoxindoles through domino Michael-Aldol reactions between isatin derived alkenes and pentane-1,5-dial in the presence of diphenylprolinol silyl ether as an aminocatalyst. As a result, a series of multistereogenic and functionalized spirocyclohexaneoxindoles have been obtained in good yields with moderate diastereoselectivities and excellent enantioselectivities. In addition, electronic circular dichroism (ECD) spectroscopy and time-dependent density functional theory (TD-DFT) were used to investigate the rational structures of spirocyclohexaneoxindoles.
authors.affiliation: Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, PR China.
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Huang
authors.forename: Zhao-Min
authors.initials: ZM
authors.lastname: Liu
authors.forename: Zhi-Cong
authors.initials: ZC
authors.lastname: Geng
authors.forename: Shao-Yun
authors.initials: SY
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Xing-Wang
authors.initials: XW
authors.lastname: Wang
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D003510:Cyclohexanes / Q000138:chemical synthesis / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry*; D007510:Isatin / Q000737:chemistry*; D008958:Models, Molecular; D000078183:Oxindoles; D013141:Spiro Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D000475:Alkenes; D003510:Cyclohexanes; D007211:Indoles; D000078183:Oxindoles; D013141:Spiro Compounds; C022960:2-oxindole; C506365:Cyclohexane; D007510:Isatin