A Synthesis of Spirooxindole-Isoindolinones Through Ugi Reaction Followed by Copper-Catalyzed Tandem C?N/C?C Coupling Process
A synthesis of spiroindolinone-isoindolinone skeletons is presented. The protocol is through a Ugi four-component reaction followed by highly efficient and mild copper-catalyzed intramolecular tandem C?N/C?C coupling process. Control experiments demonstra
Organocatalytic double arylation of 3-isothiocyanato oxindoles: Stereocontrolled synthesis of complex spirooxindoles
Quinones, precursors of aromatic structures, were firstly employed as the electrophiles for the organocatalytic Michael addition/cyclization cascade reaction with versatile 3-isothiocyanato oxindoles. Chiral bifunctional organocatalyst was appropriate for this enantioselective transformation to afford a variety of novel spirooxindoles, possessing a spirocyclic stereocenter adjacent to the aromatic ring, via asymmetric double arylation. These synthesized spirooxindoles are very difficult to access by the reported methods and were obtained in excellent chemical yields with excellent enantioselectivities.
Zhang, Lin-Lin,Da, Bing-Chao,Xiang, Shao-Hua,Zhu, Shuai,Yuan, Zi-Yun,Guo, Zhen,Tan, Bin
p. 1689 - 1696
(2018/11/25)
Asymmetric Conjugate Addition of Ethylene Sulfonyl Fluorides to 3-Amido-2-oxindoles: Synthesis of Chiral Spirocyclic Oxindole Sultams
An enantioselective conjugate addition of ethylene sulfonyl fluorides to 3-amido-2-oxindoles has been developed. Quinine-derived squaramides were identified as efficient catalysts. A series of spirocyclic oxindole sultams were prepared with excellent yields and enantioselectivities. A reaction mechanism via bifunctional activation was proposed.
Chen, Jie,Huang, Bao-Qin,Wang, Zeng-Qing,Zhang, Xue-Jing,Yan, Ming
p. 9742 - 9746
(2019/11/28)
Organocatalytic direct asymmetric aldol reactions of 3-isothiocyanato oxindoles to ketones: Stereocontrolled synthesis of spirooxindoles bearing highly congested contiguous tetrasubstituted stereocenters
Chemical equations presented. The first example of a direct catalytic asymmetric intermolecular aldol reaction of 3-isothiocyanato oxindoles to simple ketones with bifunctional thiourea-tertiary amine as catalyst is reported. This strategy provides a promising approach for the asymmetric synthesis of a range of enantioenriched spirocyclic oxindoles bearing two highly congested contiguous tetrasubstituted carbon stereocenters. Versatile transformations of the spirocyclic oxindole products into other structurally diverse spirocyclic oxindoles have also been demonstrated.