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A new method was developed for the synthesis of spiro[azepane-4,3′-indol]-2′(1′ H)-ones in yields of up to 96% with a broad substrate scope by using oxotryptamines as dual-nucleophilic reagents to react with allenoates in the presence of cesium carbonate under mild conditions. In accord with previous works and a deprotonation-tracing experiment, a plausible reaction mechanism is proposed. [ABSTRACT FROM AUTHOR]

A catalyst‐free self‐catalyzed [3+2] cycloaddition reaction of 3‐isothiocyanato oxindoles with vinylpyridines has been established, affording the desired products in high yields (up to 97 %) with moderate to good diastereoselectivities (up to 11:1) under mild conditions. The reaction mechanism has been investigated by control experiments, DFT calculations of pKa values and the kinetic studies, revealing that this reaction featured the mutual activation between 3‐isothiocyanato oxindole and vinylpyridine to generate the reactive species. Furthermore, these products could be easily transformed into the corresponding methylated and hydroxylated products under basic conditions. [ABSTRACT FROM AUTHOR]

Abstract: A catalyst‐free self‐catalyzed [3+2] cycloaddition reaction of isatin‐derived α‐(trifluoromethyl)imines with vinylpyridines is reported. The reaction offers a straightforward and atom‐economical procedure for the preparation of a series of 5′‐trifluoromethyl‐spiro[pyrrolidin‐3,2′‐oxindoles] in excellent yields and diastereoselectivities. The reaction mechanism has been investigated by control experiments, DFT calculation of pKa values and the kinetic profiles, revealing that this reaction featured the mutual activation between isatin‐derived α‐(trifluoromethyl)imines and vinylpyridine to generate the reactive species. [ABSTRACT FROM AUTHOR]

A novel cinchona-alkaloid-derived organocatalyst has been developed to catalyze the asymmetric regioselective [3+2] cycloaddition of 3-isothiocyanato oxindoles with dibenzylidene ketones. A series of spirooxindole enols could be obtained in high yields with good-to-excellent diastereo- and enantioselectivities. [ABSTRACT FROM AUTHOR]

The highly efficient organocatalytic enantioselective [3+2] cyclization of 3-isothiocyanato oxindoles with trifluoromethylated 2-butenedioic acid diesters for the synthesis of spirooxindoles possessing a CF3-containing quaternary carbon stereocenter was explored. An enantiodivergent approach for the synthesis of spirooxindoles by regulation of the temperature was demonstrated at different temperatures. The outcome of the reaction featured high diastereo- and enantioselectivities. Several interesting enantioenriched spirooxindole derivatives bearing a trifluoromethyl quaternary carbon stereocenter were synthesized from the products of this reaction. [ABSTRACT FROM AUTHOR]

A highly efficient palladium(0)-catalyzed asymmetric [3+2] cycloaddition using 3-diazooxindoles serving as dipolarophiles affords functionalized pyrazolidine derivatives in an atom-economical way. In addition, by trapping the pyrazolidine derivatives with maleimides, the corresponding spiropyrazolidine oxindoles containing multiple stereogenic centers have been obtained in high yields along with moderate to good levels of diastereoselectivity and enantioselectivity under mild conditions. Thus, a novel three-component one-pot tandem reaction has been developed. [ABSTRACT FROM AUTHOR]

The first highly enantioselective formal [4+2] tandem cyclizations between isatylidenemalononitriles and activated dienes catalyzed by bifunctional chiral phosphine catalysts have been developed, yielding multistereogenic spirocyclic oxindoles in high yields and excellent optical purity. This reaction is accomplished via a tandem Rauhut-Currier/Michael/Rauhut-Currier reaction sequence. [ABSTRACT FROM AUTHOR]

The catalytic asymmetric [3+2] cycloaddition of (3-isothiocyanato)oxindoles with azodicarboxylates has been explored in the presence of (DHQD)2PHAL. It affords spirooxindoles having two heterocycles at their C3′-position in excellent yields, with high enantioselectivities, and under mild conditions within 5 min. Moreover, another spirooxindole derived from the reaction of (3-isothiocyanato)oxindole with two molecules of azodicarboxylate could also be formed in excellent yields with the same high enantioselectivities under the standard conditions. [ABSTRACT FROM AUTHOR]

The synthesis of the title compounds involves asymmetric [3 + 2] cycloaddition of 3-diazooxindoles with vinylcyclopropanes. [ABSTRACT FROM AUTHOR]

The title cyclization is accomplished via a tandem Rauhut-Currier/Michael/Rauhut-Currrier reaction sequence to give spirocyclic oxindoles in high yields along with excellent enantio- and diastereoselectivities. [ABSTRACT FROM AUTHOR]

A novelasymmetric formal [3+2] cycloaddition of vinyl cyclopropanes and isatinsin the presence of Pd2(dba)3and the chiralimidazoline-phosphine ligand (aS,R,R)-L3has been developed, affording the corresponding highly functionalizedoxindole-fused spirotetrahydrofuran frameworks in good yields alongwith good diastereo- and high enantioselectivities under mild conditions. [ABSTRACT FROM AUTHOR]

in the presence of chiral imidazoline-phosphine ligands [ABSTRACT FROM AUTHOR]

A novel cinchona alkaloid derived amine catalyzes the [3 + 2] cycloaddition of oxindoles with 2-butenedioc acid esters to produce spirooxindoles with high diastereo-and enantioselectivity. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Enantioselective Synthesis of Spirooxindoles: Asymmetric [3 + 2] Cycloaddition of (3-Isothiocyanato)oxindoles with Azodicarboxylates" by Y. Jiang and others, published in the periodical "European Journal of Organic Chemistry" in 2013.

The reactions are catalyzed by a novel Cinchona alkaloid-derived organocatalyst and different spirocyclic products are obtained depending on the reaction conditions and the ratios of reagents. [ABSTRACT FROM AUTHOR]