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An efficient method to construct unique spiro[indoline-3,4'-pyrrolo[3,4- b ]pyridines] was successfully developed via a DABCO promoted formal [3 + 3] cycloaddition reaction of MBH carbonates of isatins with β-enamino maleimides in acetonitrile at room temperature. This reaction afforded multifunctionalized spiro[indoline-3,4'-pyrrolo[3,4- b ]pyridines] and spiro[dipyrrolo[3,4- b :3',4'- e ]pyridine-8,3'-indolines] in good yields and with lower diastereoselectivity. The relative configuration of the two diasteromers of the spiro compounds was clearly elucidated by the determination of eight single crystal structures.

Under the catalysis of p-TsOH, ß-enamino esters, generated in situ from the reaction of arylamines and propiolate, were reacted with isatins to afford isatinylidene bis(3-arylamino)acrylates in moderate yields. When BF3·OEt2 was used as catalyst, similar reactions of the in situ generated ß-enamino esters resulted in the corresponding spiro[indoline-3,4'-pyridine] derivatives in good yields.

DABCO promoted one‐pot three‐component reaction of aromatic amines, dialkyl but‐2‐ynedioates and MBH nitriles of isatins selectively afforded two diastereomeric spiro[indoline‐3,4′‐pyridines] in comparable yields. On the other hand, DABCO promoted cyclization of dialkyl but‐2‐ynedioates and MBH carbonates of isatins in DCM at room temperature gave spiro[cyclopentane‐1,3′‐indoline] derivatives, while the reaction of dialkyl but‐2‐ynedioates and MBH nitriles of isatins in chloroform at 70 °C resulted in unique cyclopenta[c]quinolone derivatives with ring‐opening of isatin moiety. A plausible reaction mechanism was rationally proposed to explain formation of the different products. [ABSTRACT FROM AUTHOR]

The base catalyzed aldol condensation of various N‐benzylisatins with 1‐acetyl‐N‐arylcyclopropanecarboxamides resulted in functionalized 3‐hydroxyoxindolin‐2‐ones in high yields, which were in turn successfully transferred to functionalized 6‐(2‐oxoindolin‐3‐yl)‐5‐azaspiro[2.4]heptanes in acetic acid in the presence of the concentrated hydrochloric acid by sequential acid catalyzed dehydration and aza‐Michael addition process. The 1H NMR spectra and the single crystal structure indicated that the obtained functionalized 6‐(2‐oxoindolin‐3‐yl)‐5‐azaspiro[2.4]heptanes have a S,S‐configuration. [ABSTRACT FROM AUTHOR]

Abstract: Triethylamine promoted cycloaddition reaction of N‐alkoxycarbonylmethylquinolinium bromide with isatylidene malononitriles afforded diastereoisomeric spiro[indoline‐3, 2′‐pyrrolo[1, 2‐a]quinolines] in satisfactory yields. The similar 1,3‐dipolar cycloaddition with N‐(p‐nitrobenzyl)quinolinlium bromide gave spiro[indoline‐3, 2′‐pyrrolo[1, 2‐a]quinolines] in good yields and with high diastereoselectivity. More importantly, the sequential cycloaddition reaction and oxidation reaction with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) resulted in novel 2‐(2‐oxoindolin‐3‐ylidene)‐2‐(2‐(dicyanomethylene)quinolin‐1‐yl)acetates. [ABSTRACT FROM AUTHOR]

Triethylamine-promoted domino cyclodimerization reaction of 3-phenacylideneoxindolines with amino ester hydrochlorides in acetonitrile afforded substituted dispiro[indoline-3,1′-cyclopentane-3′,3″-indolines] in good yields. The relative configuration of the major diastereoisomers was determined by the X-ray diffraction analysis of three single crystal structures. [ABSTRACT FROM AUTHOR]

A unique two-carbon ring expansion of isatin has been achieved to conveniently construct the functionalized dibenzo[b,d]azepin-6-one scaffold in moderate to high yields, and the two carbon sources are different: one carbon is from the N-substituent of pyridinium bromide and the other is from indene-1,3-dione. [ABSTRACT FROM AUTHOR]

Diverse functionalized spiro[indoline-3,4 $$^{\prime }$$ -pyrrolo[3,4-b]pyridines] were efficiently synthesized by the three-component reaction of 3-arylamino-1-methyl- $$1H$$ -pyrrole-2,5-dione, isatins and malononitrile (ethyl cyanoacetate) in ethanol in the presence of triethylamine. This reaction not only provided a convenient synthetic method for the construction of a versatile spirooxindole system, but also access to reactive $$\upbeta $$ -enaminone and its derivatives for organic and medical chemistry. Graphic Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This unprecedented title reaction is also applicable to the synthesis of compound (IV) by using acenaphthenequinone instead of isatin. [ABSTRACT FROM AUTHOR]

In the presence of hexamethylphosphorous triamide, the reaction of isatin with arylidene pivaloylacetonitriles in dry methylene dichloride afforded functionalized spiro[cyclopropane-1,3′-indolines] in good yields and with high diastereoselectivity. Moreover, the similar reaction of isatins with isatylidene malononitriles predominately gave spiro[indoline-3,1′-cyclopropane-2′,3″-indolines] in very high yields with two indoline moieties in trans -configuration. [ABSTRACT FROM AUTHOR]

Abstract: An efficient synthetic procedure for the complex dispirooxindoline fused [1,3]oxazines was successfully developed via Diels–Alder reaction of (E)-1,3-dihydro-3-phenacylidene-2H-indol-2-ones with 1,2-dihydro-2-oxospiro[3H-indole-3,2′-[2H,9aH-pyrido[2,1-b][1,3]oxazines], which were obtained from three-component reactions of pyridine and isatins with acetylenedicarboxylate or propiolate. 1H NMR data and single crystal structures indicated that this reaction has both high regioselectivity and diastereoselectivity. [Copyright &y& Elsevier]

Abstract: An efficient synthetic method for 1′-aryl-2′-(2-oxoindolin-3-yl)spiro[indoline-3,5′-pyrroline]-2,3′-diones was successfully developed via the one-pot domino reaction of arylamines, acetone, and isatins in acetic acid. The reaction mechanism involved the sequential Michael addition and ring closure of the in situ formed 3-N-aryliminoisatin and isatylidene acetone. [Copyright &y& Elsevier]

Abstract: In the presence of p-toluenesulfonic acid as the catalyst the three-component reactions of arylamines, acetylenedicarboxylates, and isatins showed very interesting molecular diversity. When equal amount of arylamine was used, the three-component reaction resulted in the high yields of functionalized 3′-hydroxyspiro[indoline-3,5′-pyrroline]-2,2′-dione derivatives. On the other hand the functionalized 3′-N-arylaminospiro[indoline-3,5′-pyrroline]-2,2′-diones were also successfully prepared in satisfactory yields by using 2M arylamine in the reaction. [Copyright &y& Elsevier]

Abstract: An efficient synthetic method for the pentasubstituted pyrroles was successfully developed via the one-pot domino reactions of arylamines, acetylenedicarboxylates, and 3-phenacylideneoxindoles. The reaction mechanism involved the sequential Michael addition and ring closure of the in situ generated β-active enamino ester. [Copyright &y& Elsevier]

An abstract of the article "Two-Carbon Ring Expansion of Isatin: A Convenient Construction of a Dibenzo[b,d]azepinone Scaffold." by Rong-Guo Shi and colleagues is presented.

Spiro[indoline-3,3′-pyrrolizines] (IV), (VI) and (VIII) are obtained by normal 1,3-cycloaddition reaction of α-amino acids, isatins, and but-2-ynedioates. [ABSTRACT FROM AUTHOR]

A three-component reaction of N-arylaldimines with isatin and dialkylacetylene dicarboxylates is developed to yield diastereomeric mixtures of spirocyclic indoline-oxazine derivatives. [ABSTRACT FROM AUTHOR]