Catalytic Asymmetric Synthesis of Cyclopentene-spirooxindoles Bearing Vinylsilanes Capable of Further Transformations
作者:Angel A. Cobo、Brittany M. Armstrong、James C. Fettinger、Annaliese K. Franz
DOI:10.1021/acs.orglett.9b02852
日期:2019.10.18
for the enantioselective formation of cyclopentene-spirooxindoles containing vinylsilanes. Using a Sc(OTf)2/PyBOX/BArF complex, the spiroannulation of allenylsilanes affords products with >94:6 dr and >90:10 er. The effect of the counterion and ligand to control selectivity is discussed. The transformation of the vinylsilane is demonstrated using cross-coupling, epoxidation, and Tamao–Fleming oxidation
Iodide-Mediated Synthesis of Spirooxindolo Dihydrofurans from Iodonium Ylides and 3-Alkylidene-2-oxindoles
作者:Benjamin A. Laevens、Jason Tao、Graham K. Murphy
DOI:10.1021/acs.joc.7b01639
日期:2017.11.17
An iodide-mediated reaction between cyclic iodonium ylides of 1,3-dicarbonyls and 3-alkylidene-2-oxindoles results in 3H-spiro[furan-2,3′-indolin]-2′-ones. The reaction was tolerant to substitutions on both the alkylidene and ylide substrates and provided access to 19 new, densely functionalized polycyclic spirocycles in typically high yield.
Solvent-free iodine-promoted synthesis of 3,2′-pyrrolinyl spirooxindoles from alkylidene oxindoles and enamino esters under ball-milling conditions
作者:Hui Xu、Hong-Wei Liu、Hao-Sheng Lin、Guan-Wu Wang
DOI:10.1039/c7cc08306h
日期:——
A solvent-free mechanochemical reaction of alkylidene oxindoles with enamino esters via an iodine-promoted tandem Michael/cyclization sequence has been developed to provide a variety of spirocyclic oxindoles in moderate to good yields with excellent diastereoselectivities.
Construction of dispirocyclohexanes via amine-catalyzed [2 + 2 + 2] annulations of Morita–Baylis–Hillman acetates with exocyclic alkenes
作者:Rongshun Chen、Silong Xu、Xia Fan、Hanyuan Li、Yuhai Tang、Zhengjie He
DOI:10.1039/c4ob01927j
日期:——
Amine-catalyzed [2 + 2 + 2] annulations of one molecule of Morita–Baylis–Hillman (MBH) acetates 1 with two molecules of 2-(arylmethylidene)indane-1,3-diones 2 or methyleneindolinones 4 have been developed under very mild conditions, which produce multistereogenic dispirocyclohexanes 3 and 5, respectively, in moderate to excellent yields and good diastereoselectivity. This amine-catalyzed annulation constitutes
N-Iodosuccinimide-Promoted Selective Construction of Cyclopropyl and Dihydrofuranyl Spirooxindoles from Alkylidene Oxindoles and Annular β-Dicarbonyl Compounds
ed cyclization of readily available alkylidene oxindoles with annular β-dicarbonylcompounds has been demonstrated. With five-membered cyclic β-dicarbonylcompounds as the starting materials, a series of cyclopropyl oxindoles can be obtained in good to excellent yields, whereas the method affords dihydrofuranyl spirooxindoles almost quantitatively when six- or seven-membered cyclic β-dicarbonyl compounds