Enantioselective Construction of Bispirooxindoles via Squaramide‐Catalysed Cascade Michael/Cyclization Reaction
作者:Bo‐Liang Zhao、Ye Lin、Da‐Ming Du
DOI:10.1002/adsc.201900358
日期:2019.7.11
2‐(2‐oxoindolin‐3‐yl)malononitriles bearing multiple active sites were first used in asymmetric catalytic synthesis, which have been successfully applied to develop a bifunctional squaramide‐catalyzed cascade Michael/cyclizationreaction strategy. Various cyclopentene‐bispirooxindoles with three continuous stereocenters, two of which are quaternary spiro‐stereocenters, were constructed in good yields with excellent stereoselectivities
Based on a novel umpolung strategy, an efficient and highlyenantioselective cascade aldol/cyclization/tautomerization of the 2-(2-oxoindolin-3-yl)malononitrile to active carbonyl compounds with excellent diastereo- and enantioselectivity has been developed. Also, various enantio-enriched multifunctional dispiro[2-amino-4,5-dihydrofuran-3-carbonitrile]bisoxindoles with adjacent spiro-stereocenters
[3+2]-Annulation of oxindolinyl-malononitriles with Morita–Baylis–Hillman acetates of nitroalkenes for the regio- and diastereoselective synthesis of spirocyclopentane-indolinones
作者:Abhishek Pareek、Sudheesh T. Sivanandan、Shweta Bhagat、Irishi N.N. Namboothiri
DOI:10.1016/j.tet.2022.132650
日期:2022.2
highly regio- and stereoselective [3 + 2] annulation with 1,3-bielectrophilic nitroallylic acetates leading to spirocyclopentane-indolinones. The reaction takes place in the presence of DABCO in THF at room temperature and affords the multi-functional spirocyclic compounds possessing three chiral centers, including a spiro-chiral center in good to excellent yields and short reaction time. The key role
Asymmetric Synthesis of Spirocyclopentane Oxindoles
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[2+3] Annulation with 2‐(2‐Oxoindolin‐3‐yl)malononitriles as 1,2‐Carbon Bisnucleophiles
作者:Yue‐Yan Ai、Dong‐Ai Li、Guo Li、He‐Ping Li、Xiang‐Hong He、Xue‐Ju Fu、Yu‐Ting Wang、Gu Zhan、Bo Han
DOI:10.1002/adsc.202100235
日期:2021.7
Carbon bisnucleophiles are important building blocks in organic synthesis and have widespread applications in the construction of carbocyclic compounds. Among them, 1,2-carbon bisnucleophile has been much less explored. Herein, we developed a [2+3] annulation of 2-(2-oxoindolin-3-yl)malononitrile with 2-nitroallylic acetates, where 2-(2-oxoindolin-3-yl)malononitrile served as a new type of 1,2-carbon
spirocyclopenteneoxindoles is an attractive target due to their potential biological activity. This work described the thiourea/silver dual catalytic (3 + 2)/Conia-ene type reaction of 2-(2-oxoindolin-3-yl)malononitrile with ortho-ethynyl substituted nitrostyrene. The reaction features mild conditions and good atom- and step-economy. Three new C–C bonds were formed within one synthetic step, providing