Synthesis of (E)-oxindolylidene acetate using tandem palladium-catalyzed Heck and alkoxycarbonylation reactions

Synthesis of Bis-Heterocycles Bearing Methyleneindole Motifs by Pd-Catalyzed Domino Reaction

A highly robust, general, and practically simple palladium-catalyzed domino bicyclization strategy is presented to synthesize nitrogen-containing bis-heterocycles bearing methylene indole motifs from alkyne-tethered carbamoyl chlorides and β,γ- or γ,δ-unsaturated hydrazones. The salient features of this transformation include broad substrate scope, good functional group tolerance, ease for scale-up, and convenient conversion.

Hauser-Kraus Annulation Initiated Multi-Cascade Reactions for Facile Access to Functionalized and Fused Oxazepines, Carbazoles and Phenanthridinediones

The Hauser-Kraus (H-K) annulation of N-unsubstituted 3-olefinic oxindoles with 3-nucleophilic phthalides triggers a cascade of ring expansion and ring contraction reactions through several regioselective steps in one pot. While oxazepines were isolated in the presence of stoichiometric amounts of base at room temperature, carbazoles and phenanthridinediones were the products in the presence of excess base and microwave irradiation. Mechanistic studies guided by stepwise reactions and control experiments revealed that the isolable oxazepine intermediate, formed via ring expansion of the H-K adduct, is the key precursor to carbazole and phenanthridinedione via decarboxylative regioselective cyclizations.

Design, synthesis and evaluation of novel 2-oxoindoline-based acetohydrazides as antitumor agents

In our search for novel small molecules activating procaspase-3, we have designed and synthesized two series of novel (E)-N'-arylidene-2-(2-oxoindolin-1-yl)acetohydrazides (4) and (Z)-2-(5-substituted-2-oxoindolin-1-yl)-N'-(2-oxoindolin-3-ylidene)acetohydrazides (5). Cytotoxic evaluation revealed that the compounds showed notable cytotoxicity toward three human cancer cell lines: colon cancer SW620, prostate cancer PC-3, and lung cancer NCI-H23. Especially, six compounds, including 4f–h and 4n–p, exhibited cytotoxicity equal or superior to positive control PAC-1, the first procaspase-3 activating compound. The most potent compound 4o was three- to five-fold more cytotoxic than PAC-1 in three cancer cell lines tested. Analysis of compounds effects on cell cycle and apoptosis demonstrated that the representative compounds 4f, 4h, 4n, 4o and 4p (especially 4o) accumulated U937 cells in S phase and substantially induced late cellular apoptosis. The results show that compound 4o would serve as a template for further design and development of novel anticancer agents.

Design, Synthesis of New 1,2,4-Triazole/1,3,4-Thiadiazole with Spiroindoline, Imidazo[4,5-b]quinoxaline and Thieno[2,3-d]pyrimidine from Isatin Derivatives as Anticancer Agents

The current work aims to design and synthesis a new series of isatin derivatives and greatly enhances their cytotoxic activity. The derivatives 3-((bromophenyl) imino)-1-(morpholino (pyridine) methyl) indolin-2-one, 2-((oxoindoline) amino) benzoic acid, 3-(thiazolo-imino) indolinone, ethyl-2-((oxoindolin-3-ylidene)amino)-benzothiophene-3-carboxylate, 1-(oxoindoline)-benzo[4,5] thieno [2,3-d]pyrimidin-4(1H)-one, ethyl-2-(2-oxoindoline) hydrazine-1-carboxylate, N-(mercapto-oxo-pyrimidine)-2-(oxoindoline) hydrazine-1-carboxamide, N-(oxo-thiazolo[3,2-a] pyrimidine)-2-(oxoindolin-ylidene) hydrazine-carboxamide, 3-((amino-phenyl) amino)-3-hydroxy- indolinone, 3-((amino-phenyl) imino)-indolinone, 2-(2-((oxoindoline) amino) phenyl) isoindolinone, 2-(oxoindoline) hydrazine-carbothioamide, 5'-thioxospiro[indoline-3,3'-[1,2,4]triazolidin]-one, 5'-amino-spiro[indoline-3,2'-[1,3,4]thiadiazol]-2-one and 3-((2-thioxo-imidazo[4,5-b]quinoxaline) imino) indolinone were synthesized from the starting material 1-(morpholino (pyridine) methyl) indoline-2,3-dione and evaluated for their in vitro cytotoxic activity against carcinogenic cells. The new chemical structures were evidenced using spectroscopy (IR, NMR and MS) and elemental analysis. The results show that compounds imidazo[4,5-b]quinoxaline-indolinone, thiazolopyrimidine-oxoindoline, pyrimidine-oxoindoline-hydrazine-carboxamide, spiro[indoline-3,2'-[1,3,4] thiadiazol]-one and spiro[indoline-3,3'-[1,2,4]triazolidin]-one have excellent anti-proliferative activities against different human cancer cell lines such as gastric carcinoma cells (MGC-803), breast adenocarcinoma cells (MCF-7), nasopharyngeal carcinoma cells (CNE2) and oral carcinoma cells (KB).

Inversion kinetics of some E/Z 3-(benzylidene)-2-oxo-indoline derivatives and their in silico CDK2 docking studies

The structure-based design of some CDK2 inhibitors with a 3-(benzylidene)indolin-2-one scaffold as potential anticancer agents was realized. Target compounds were obtained as E/Z mixtures and were resolved to corresponding E- and Z-diastereomers. In silico studies using MOE 2019.01 software revealed better docking on the targeted enzyme for the Z-diastereomer compared to the E-one. A time-dependent kinetic isomerization study was carried out for the inversion of E/Z diastereomers in DMSO-d6 at room temperature, and were found to obey the first order kinetic reactions. Furthermore, a determination of the kinetic inter-conversion rate order by graphical analysis method and calculation of the rate constant and half-life of this kinetic process were carried out. For the prediction of the stability of the diastereomer(s), a good multiple regression equation was generated between the reaction rates of isomerization and some QM parameters with significant p value.

Total Synthesis of Cyclopiamide A Using Palladium-Catalyzed Domino Cyclization

Total synthesis of cyclopiamide A was accomplished using a palladium-catalyzed domino cyclization. Three rings in the tetracyclic skeleton of cyclopiamide A were constructed in a one-step domino reaction incorporating double carbopalladation and C-H activation.

Isatin and its derivatives: a survey of recent syntheses, reactions, and applications

Isatin (1H-indole-2,3-dione) and its derivatives represent an important class of heterocyclic compounds that can be used as precursors for drug synthesis. Since its discovery, a lot of research work has been done regarding the synthesis, chemical properties, and biological and industrial applications of isatin. In this review, we have reported several novel methods for the synthesis of N-, C2-, and C3-substituted and spiro derivatives of isatin. The isatin moiety also shows important chemical reactions such as oxidation, ring expansion, Friedel-Crafts reaction and aldol condensation. These reactions, in turn, produce several biologically viable compounds like 2-oxindoles, tryptanthrin, indirubins, and many more. We have also summarized some recently reported biological activities exhibited by isatin derivatives, like anti-cancer, anti-bacterial, anti-diabetic and others. Special attention has been paid to their anti-cancer activity, and various anti-cancer targets such as histone deacetylase, carbonic anhydrase, tyrosine kinase, and tubulin have been discussed in detail. Other applications of isatin derivatives, such as in the dye industry and in corrosion prevention, have also been discussed.

When Ethyl Isocyanoacetate Meets Isatins: A 1,3-Dipolar/Inverse 1,3-Dipolar/Olefination Reaction for Access to 3-Ylideneoxindoles

A new CuI/1,10-phen-catalyzed reaction for the synthesis of 3-ylideneoxindoles from readily available isatins and ethyl isocyanoacetate, in which ethyl isocyanoacetate acts as a latent two-carbon donor like the Wittig reagent, is reported. A tandem procedure including 1,3-dipolar cycloaddition/inverse 1,3-dipolar ring opening/olefination allows the preparation of 3-ylideneoxindoles with broad functional group tolerance.

Domino carbometalation/coupling reactions of N-arylpropiolamides: a novel and promising synthetic strategy toward stereocontrolled preparation of highly substituted 3-methyleneindolinones

3-Methyleneindolinone derivatives are important structural motifs found in many compounds of natural occurrence and pharmacological significance.

TiCl4/DMAP mediated Z-selective knovenagel condensation of isatins with nitroacetates and related compounds

A Z-selective Knovenagel condensation reaction of isatins with nitroacetates and related compounds mediated by TiCl₄ and DMAP was described.