Synthesis of CF3-Containing 3,3′-Cyclopropyl Spirooxindoles by Sequential [3 + 2] Cycloaddition/Ring Contraction of Ylideneoxindoles with 2,2,2-Trifluorodiazoethane
摘要:
A [3 + 2] cycloaddition/ring contraction sequence of ylideneoxindoles with in situ-generated 2,2,2-trifluorodiazoethane without the use of any transition-metal catalyst has been developed. The reaction provides efficient access to biologically important and synthetically useful CF3-containing 3,3'-cyclopropyl spirooxindoles in high yield (74-99%) with high diastereoselectivity (>95:5 d.r.).
Take two: By employing two equivalents of an aldehyde in an asymmetricorganocatalyticdominoreaction, the nucleophilic enamine intermediate is also converted into the corresponding iminium species through oxidation with o‐iodoxybenzoic acid. Thus, polyfunctionalized cyclohexene derivatives are formed from two simple starting materials in good yields and stereoselectivities (see scheme; Bn=benzyl
A novel and diastereoselective construction of H-pyrazolo[3,2-a]isoquinoline fused spirooxindoles via [3+2] cycloaddition
作者:Panneerselvam Yuvaraj、Boreddy S.R. Reddy
DOI:10.1016/j.tetlet.2013.11.116
日期:2014.1
A one-pot, highly efficient and diastereoselective construction of 1,2-dihyro-10′bH-spiro[indole-3,1′-pyrazole[3,2-a]isoquinoline]-2′-carboxylates via silver triflate-catalyzed [3+2] cycloaddition of N′-(2–alkynylbenzylidene)hydrazide with methyleneindolinones in good to excellent yield has been described. The transformation involves initially a condensation followed by 6-endo-intramolecular cyclization
作者:Carlos J.A. Ribeiro、S. Praveen Kumar、Rui Moreira、Maria M.M. Santos
DOI:10.1016/j.tetlet.2011.10.139
日期:2012.1
The synthesis of spiroisoxazoline oxindoles containing ester groups at position 4′ and aromatic or ester groups at position 3′ of the isoxazoline ring is reported. The compounds were synthesized in yields up to 94% by 1,3-dipolar cycloaddition of 3-methylene indolin-2-ones and chlorooximes in the presence of triethylamine or zinc.
Pseudo-Five-Component Reaction for Diastereoselective Synthesis of Butterfly Shaped Bispiro[Oxindole-Pyrrolidine]s
作者:Xiaofeng Zhang、Weiqi Qiu、Stephanie A. Murray、Desheng Zhan、Jason Evans、Jerry P. Jasinski、Xiao Wang、Wei Zhang
DOI:10.1021/acs.joc.1c01797
日期:2021.12.3
A pseudo-five-component reaction involving double decarboxylative 1,3-dipolar cycloaddition of azomethine ylides with olefinic oxindoles for the diastereoselectivesynthesis of bispiro[oxindole-pyrrolidine]s is developed. The major diastereomers are unique butterfly shaped compounds with a plane of symmetry. Recyclable zeolite HY acid catalyst is used to promote the reaction, and only CO2 and H2O are
<i>N</i>-Heterocyclic Carbene Catalytic [4 + 2] Cyclization of 3-Alkylenyloxindoles with Enals: γ-Carbon Activation for Enantioselective Assembly of Spirocarbocyclic Oxindoles
作者:Hong Yao、Yu Zhou、Xia Chen、Pengfei Zhang、Jinyi Xu、Hong Liu
DOI:10.1021/acs.joc.6b01596
日期:2016.10.7
ubiquitous structure of all-carbospirocyclic oxindoles makes the development of new methods for their enantioselective and stereoselective synthesis a significant ongoing challenge. Herein, we disclose a formal [4 + 2] annulationthrough N-heterocyclic carbene (NHC) catalysis for highly enantioselectivesynthesis of intriguing spirocarbocyclic oxindoles in the presence of Lewis acids. This protocol features