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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.

The base promoted domino reaction of bindone ([1,2'-biindenylidene]-1',3,3'-trione) with common 1,3-dipolarophiles showed interesting molecular diversities, from which the unique spiro and fused indeno[1,2- a ]fluorine derivatives were conveniently synthesized in satisfactory yields. In the presence of a base, bindone underwent formal [3 + 3] cycloaddition with satylidene malononitriles to give dispiro[indene-2,4'-fluorene-1',3''-indoline]. It also underwent formal [4 + 2] cycloaddition with 4-arylidene-pyrazol-3-ones to give diastereoisomeric spiro[indeno[1,2- a ]fluorene-5,4'-pyrazole]. On the other hand, a triethylamine promoted reaction of three molecules of 1,3-indanediones and isatins in toluene afforded spiro[diindeno[2,1- b :2',1'- d ]anthracene-11,3'-indoline] derivatives through the domino [4 + 2] cycloaddition and ring-expansion process.

A DABCO-promoted annulation reaction of bindone ([1,2'-biindenylidene]-1',3,3'-trione) and 3-methyleneoxindoles showed very interesting molecular diversity under different reaction conditions. The base-promoted annulation reaction of bindone and 3-phenacylideneoxindoles in DCM at room temperature afforded spiro[indeno[1,2- a ]fluorene-5,3'-indoline] derivatives in good yields and with high diastereoselectivity. However, the similar reaction of 2-(2-oxoindolin-3-ylidene) acetates resulted in Z / E -isomeric spiro[indeno[1,2- a ]fluorene-5,3'-indolines] with diastereomeric ratios of 2:1 to 10:1. On the other hand, the DABCO-promoted annulation reaction of bindone and 3-methyleneoxindoles in acetonitrile at different temperatures selectively gave spiro[benzo[5,6]pentaleno[1,6 a - b ]naphthalene-7,3'-indoline] derivatives and complex dispiro[indoline-3,6'-[4 b ,6 a ]ethanoindeno[1,2- a ]fluorene-14',3″-indolines] in satisfactory yields.

p -TsOH catalyzed Diels-Alder reaction of 2-(1-alkylindol-3-yl)naphthalene-1,4-diones and 3-phenacylideneoxindoles showed fascinating diastereoselectivity. The reaction with the hydrated p -TsOH afforded trans -isomers of dihydrospiro[indoline-3,6'-naphtho[2,3- c ]carbazoles] as major products. Alternatively, the reaction with anhydrous p -TsOH under a Dean and Stark apparatus predominately gave cis -isomer of dihydrospiro[indoline-3,6'-naphtho[2,3- c ]carbazoles]. On the other hand, the similar p -TsOH catalyzed reaction of 2-(indol-3-yl)naphthalene-1,4-diones with 3-arylideneindolin-2-ones afforded cis / trans -isomers of dihydrospiro[indoline-3,6'-naphtho[2,3- c ]carbazoles]. Additionally, the p -TsOH catalyzed reaction of 2-(indol-3-yl)naphthalene-1,4-diones with 2-arylidene-1,3-indanediones gave the expected spiro[indene-2,6'-naphtho[2,3- c ]carbazoles] in satisfactory yields.

The three-component reaction of N-benzylbenzimidazole, dialkyl acetylenedicarboxylate, and N-alkylisatins in tetrahydrofuran at room temperature afforded the novel functionalized benzimidazole[2.1-b][1,3]oxazine spirooxindoles in good yields. (1)H NMR spectra indicated that two diastereoisomers with a ratio of 1:3-1:6 exist in the obtained spirooxindole derivatives.

Diverse functionalized spiro[indoline-3,4'-pyrrolo[3,4-b]pyridines] were efficiently synthesized by the three-component reaction of 3-arylamino-1-methyl-H-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 β-enaminone and its derivatives for organic and medical chemistry.

The reactions of vinyl malononitriles with 3-phenacylideneoxindoles in ethanol in the presence of DBU as base resulted in the functionalized spirocyclic oxindoles through the domino Michael addition and intramolecular nucleophilic addition to cyano group. On the other hand, the similar reaction in the presence of piperidine as base afforded the simple Michael addition products in good yields. The stereochemistry of the spirooxindoles was established with (1)H NMR data and single crystal structures.

The three-component reactions of substituted pyridines, dimethyl acetylenedicarboxylates, and 3-phenacylideneoxindoles afforded spiro[indoline-3,1'quinolizines] in high yields and with high diastereoselectivity. The Diels-Alder reactions of spiro[indoline-3,1' quinolizines] with maleic anhydride and N- phenyl maleimides successfully resulted in polyfunctionalized isoquinolinuclidine derivatives. The similar three-component reactions with quinoline resulted in the novel spiro[indoline-3,4' -pyrido[1,2-a]quinolines] in moderate to good yields.

A simple protocol for the construction of novel dispirocyclopentanebisoxindoles is accomplished by the base promoted domino reactions between two molecules of 3-phenacylideneoxindoles with the participation of solvents, alcohol, or other added nucleophiles such as amines or thiophenols. Significantly, this domino reaction results in the complex dispiro compounds with high yields and diastereoselectivity, which would allow construction of dispirocyclopentanebisoxindole with four and five diastereoisomeric centers using simple materials.

A series of complex spiro[indoline-3,3'-pyrrolo[1,2-a]quinolines] were efficiently synthesized by 1,3-dipolar cycloaddition reactions of N-phenacylquinolinium bromides with 3-phenacylideneoxindoles in ethanol with triethylamine as base. Under similar conditions the 1,3-cycloadditions of N-phenacylisoquinolinium and N-phenacyl-1,10-phenanthrolinium bromides with 3-phenacylideneoxindoles resulted in the corresponding spiro[indoline-3,1'-pyrrolo[2,1-a]isoquinoline] and spiro[benzo[h]pyrrolo[1,2-a]quinoline-3,3'-indoline] derivatives in good yields. The characterization data of spiro compounds and single crystal determination indicated that this 1,3-cycloaddition reaction is a regioselective and diastereoselective reaction and all prepared spiro compounds exist in the thermodynamically stable trans isomer.

A facile synthetic protocol was developed for the efficient synthesis of complex dispirooxindole-fused heterocycles via a three-component reaction. The key strategies involve a domino 1,4-dipolar addition and Diels-Alder reaction of the in situ generated Huisgen 1,4-dipoles from the addition reaction of 4-dimethylaminopyridine with acetylenedicarboxylate to 3-phenacylideneoxindole.

The three‐component reaction of isoquinoline, dialkyl but‐2‐ynedioate and 4‐arylidene‐5‐methyl‐2‐phenylpyrazol‐3‐ones in acetonitrile at room temperature gave functionalized spiro[pyrazole‐4,1′‐pyrido[2,1‐a]isoquinolines] in satisfactory yields with cis/cis‐diastereoisomer as major product. On the other hand, the similar three‐component reaction with quinoline afforded both cis/cis‐ and cis/trans‐isomeric spiro[pyrazole‐4,4′‐pyrido[1,2‐a]quinolines] in nearly comparable yields. The reaction was finished with in situ generation of Huisgen' 1,4‐dipole, sequential Michael addition and annulation reaction process. [ABSTRACT FROM AUTHOR]

DDQ promoted the reaction of 3-(indol-3-yl)-1,3-diphenylpropan-1-ones with 3-methyleneoxindoles in refluxing ethanol resulting in functionalized dihydrospiro[carbazole-1,3′-indolines] in good yields and with high diastereoselectivity. Similar reactions with 5-arylidene-1,3-dimethylbarbituric acids also afforded functionalized spiro[carbazole-1,5′-pyrimidines] in satisfactory yields. The reaction actually proceeded via the DDQ oxidative dehydrogenation of 3-(indol-3-yl)-1,3-diphenylpropan-1-ones to the corresponding 3-vinylindoles, their sequential Diels–Alder reaction with dienophiles and further isomerization process. DFT calculations showed that the Diels–Alder reaction has a normal electron-demanding character. [ABSTRACT FROM AUTHOR]

The acetic acid catalyzed three‐component reaction of pyrrolidine, aromatic aldehydes and 4‐arylidene‐5‐methyl‐2‐phenylpyrazol‐3‐one in refluxing toluene gave functionalized 7′‐(E)‐benzylidenespiro[pyrazole‐4,1′‐pyrrolizines] in good yields and with high diastereoselectivity. The similar reaction with 2‐arylidene‐N,N'‐dimethylbarbiturates resulted in mixture of Z/E‐isomers of 7′‐ arylidenespiro[pyrimidine‐5,1′‐pyrrolizines] in good yields. However, the three‐component with N‐phenylmaleimides and sequential oxidation with DDQ reaction gave 8‐(E)‐arylidenedihydropyrrolo[3,4‐a]pyrrolizines in satisfactory yields. The reaction mechanism included sequential β‐C−H functionalization of pyrrolidine, generation of conjugated azomethine ylides, and sequential [3+2] cycloaddition with active alkenes. [ABSTRACT FROM AUTHOR]

Spiro[indoline‐3,7′‐pyrrolo[1,2‐a]azepines] were conveniently synthesized in satisfactory yields and with high diastereoselectivity from three‐component reaction of L‐proline, isatins and chalcones and sequential reaction with dimethyl but‐2‐ynedioate or methyl propiolate in refluxing methanol. The ferrocenyl‐chalcones and dibenzylideneacetones were also successfully used in this one‐pot two‐step reaction to give novel ferrocenyl and styryl‐substituted spiro compounds. The reaction mechanism included domino [3+2] cycloadddtition reaction of azomethine ylide with chalcone and ring‐expansion reaction of in situ generated spiro[indoline‐3,3′‐pyrrolizine] with electron‐deficient alkynes. [ABSTRACT FROM AUTHOR]

A TEMPO promoted oxidative aza‐Diels‐Alder reaction of ketohydrazones with 3‐methyleneoxindoles or 2‐arylidene‐1,3‐indanediones were successfully developed, This reaction provided an efficient synthetic protocol for novel functionalized spiro[indoline‐3,3′‐pyridazines] and spiro[indene‐2,3′‐pyridazines]. This reaction showed high diastereoselectivity and strict substituent's electron effect, which might be due to the reaction mechanisms process including sequential oxidative generation of 1,2‐diaza‐1,3‐dien and normal electron‐demand aza‐Diels‐Alder reaction. [ABSTRACT FROM AUTHOR]

A domino annulation reaction of various α-dicarbonyl compounds with anilinosuccinimides takes place with Brønsted-acid catalysis under microwave irradiation to give functionalized spiropyrroloquinolines. The reaction involves activation of the ortho hydrogen of the different aniline derivatives. [ABSTRACT FROM AUTHOR]

Under visible-light catalysis, a domino oxidative 1,3-dipolar cycloaddition reaction of alkyl 2-(3,4-dihydroisoquinolin-2-yl)acetate with 2-arylideneindane-1,3-diones has been developed that affords functionalized spiro[indene-2,1′-pyrrolo[2,1-a]isoquinoline]s in satisfactory yields and high diastereoselectivities. Depending on the electronic properties of the aryl group, similar reactions with tert-butyl 2-(3,4-dihydroisoquinolin-2-yl)acetate and 2-(3,4-dihydroisoquinolin-2(1 H)-yl)acetonitrile selectively gave spiro[indene-2,1′-pyrrolo[2,1-a]isoquinoline]s and 3-arylspiro[indene-2,2′-oxirane]-1,3-diones, respectively. [ABSTRACT FROM AUTHOR]

A cycloaddition reaction promoted by the Lewis acid BF3 ·OEt2 between 2-arylidene-1,3-indanediones and β-enamino esters, generated by the addition of arylamines to dimethyl acetylenedicarboxylate, gave densely substituted 1,4-diphenyl-4,5-dihydro-1 H-indeno[1,2- b]pyridines in satisfactory yields. When 2-isatylidene-1,3-indanediones were used under the same conditions, the one-pot reaction gave the corresponding spiro[indeno[1,2- b]pyridine-4,3′-indolines] in high yields. On the other hand, unusual 1,2-diphenyl-2,5-dihydro-1 H-indeno[1,2- b]pyridines were obtained in moderate to good yields through a four-component reaction. [ABSTRACT FROM AUTHOR]

The four-component reactions of anilines, dialkyl acetylenedicarboxylate, acenaphthenequinone, and dimedone (or cyclohexane-1,3-dione) in provided an efficient synthetic procedure for the functionalized spiro[acenaphthylene-1,2′-quinoline] derivatives in good yields. This reaction has the advantages of using common starting material, mild reaction conditions, and operational simplicity. [ABSTRACT FROM AUTHOR]

A simple synthetic protocol has been developed for the efficient synthesis of structurally diverse 3′-aryl-2′-styryl-2′,3′-dihydrospiro[indoline-3,6′-[1,3]oxazine]-4′,5′-dicarboxylate derivatives through readily accessible three-component reactions of α,β-unsaturated N-arylaldimines, dialkyl acetylenedicarboxylate, and N-alkylisatins. When simple N-arylaldimines were utilized in the reactions, the corresponding 2′,3′-diaryl-2′,3′-dihydrospiro[indoline-3,6′-[1,3]oxazine]s were obtained in good yields. This reaction provides a potential synthetic application of the reactive 1,4-dipolar intermediates generated from the reaction of aromatic imines with electron-deficient alkynes. [ABSTRACT FROM AUTHOR]

Chemical equations are presented for the article "Diastereoselective Synthesis of Functionalized Spiro[cyclopropane-1,3′-indolines] and Spiro[indoline-3,1′-cyclopropane-2′,3′′-indolines]" by W.-J. Qi and colleagues, published in the periodical "Tetrahedron."

starting from various anilines, dialkyl acetylenedicarboxylate, acenaphthenequinone, and cyclic 1,3-dicarbonyl compounds [ABSTRACT FROM AUTHOR]

A one-pot three-component reaction of isatylidene malononitriles or ethylisatylidene cyanoacetate with dimethyl acetylene dicarboxylate and triphenylphosphine is developed to yield spirocyclic adducts (IV). [ABSTRACT FROM AUTHOR]

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]

A graphical abstract of the article "Diastereoselective Synthesis of Spiro[indene-2,2′-pyrazolo[1,2-a]pyrazoles] and Spiro[indoline-3,2′-pyrazolo[1,2-a]pyrazoles] via 1,3-Dipolar Cycloaddition" 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]