Synthesis of novel 3′-spirocyclic-oxindole derivatives and assessment of their cytostatic activities

Asymmetric synthesis of chiral 1,2-oxazinane and hexahydropyridazin spirocyclic scaffolds by organocatalytic [4 + 2] cycloaddition

A novel approach to synthesize chiral 1,2-oxazinane spirocyclic scaffolds by organocatalytic [4 + 2] cycloaddition reaction between methyleneindolinones and γ-aminooxy-α,β-unsaturated ester has been disclosed. Furthermore, a hydrazide 1,4-synthon is designed and synthesized to construct chiral hexahydropyridazin spirocyclic scaffolds with methyleneindolinones via [4 + 2] cycloaddition reaction. Both reactions give corresponding products in good to excellent yield, excellent diastereoselectivity and good enantioselectivity.

Chiral 1,2-oxazinane spiro-oxindole and chiral hexahydropyridazin spiro-oxindole skeletons are made through asymmetric organocatalytic reactions. Corresponding products were produced in good to excellent yield, excellent diastereoselectivity and good enantioselectivity.

Iron-Catalyzed Borrowing Hydrogen C-Alkylation of Oxindoles with Alcohols

A general and efficient iron-catalyzed C-alkylation of oxindoles has been developed. This borrowing hydrogen approach employing a (cyclopentadienone)iron carbonyl complex (2 mol %) exhibited a broad reaction scope, allowing benzylic and simple primary and secondary aliphatic alcohols to be employed as alkylating agents. A variety of oxindoles underwent selective mono-C3-alkylation in good-to-excellent isolated yields (28 examples, 50-92 % yield, 79 % average yield).

Synthesis of spiro[isoindole-1,5'-isoxazolidin]-3(2H)-ones as potential inhibitors of the MDM2-p53 interaction

A series of spiro[isoindole-1,5-isoxazolidin]-3(2H)-ones has been synthesized by 1,3-dipolar cycloaddition of N-benzylnitrone with isoindolin-3-methylene-1-ones. The regio- and stereoselectivity of the process have been rationalized by computational methods. The obtained compounds show cytotoxic properties and antiproliferative activity in the range of 9–22 μM. Biological tests suggest that the antitumor activity could be linked to the inhibition of the protein–protein p53-MDM2 interaction. Docking measurements support the biological data.

Oxindole: A chemical prism carrying plethora of therapeutic benefits

Oxindole has emerged as a valuable scaffold in medicinal chemistry possessing diverse range of pharmacological activities. Its value has further been increased by its natural occurrence as alkaloids in variety of plants. It was first extracted from the cat claw's plant Uncaria tomentosa found in the Amazon rainforest and other tropical areas of South and Central America. Traditionally as well as present emerging therapeutic potential of oxindole nucleus has captured the interest of medicinal chemists to synthesize novel oxindole derivatives. In the present review the authors have integrated its chemistry and synthetic strategies developed after 1945. Also the information of naturally occurring oxindole alkaloids has been incorporated. The detailed pharmacological activities including anti-cancer, anti-HIV, antidiabetic, antibacterial, antioxidant, kinase inhibitory, AChE inhibitory, anti-leishmanial, β3 adrenergic receptor agonistic, phosphatase inhibitory, analgesic, spermicidal, vasopressin antagonists, progesterone antagonists, neuroprotection, and NMDA blocker activities of oxindole derivatives alongwith their SAR has also been discussed in detail. Additionally, information regarding the oxindole derivatives in clinical trials has been incorporated. Thus, this review will provide insights for the synthetic as well as medicinal chemist for the designing and synthesis of novel oxindole derivatives with novel improved range of pharmacological implications.

Asymmetric Mannich reaction: highly enantioselective synthesis of 3-amino-oxindoles via chiral squaramide based H-bond donor catalysis

A facile formation of 3-aminooxindole derivatives from the reaction of 1,3-diketones with isatin (N-Boc) via an asymmetric Mannich reaction catalyzed by chiral cinchona alkaloid based squaramide containing H-bond donor catalysts.

Design, synthesis and biological evaluation of novel C3-functionalized oxindoles as potential Pim-1 kinase inhibitors

A novel series of C3-functionalized oxindoles, 3-(2-oxo-4-phenylbut-3-en-1-ylidene) indolin-2-ones as potential Pim-1 kinase inhibitors, were designed, synthesized and investigated for inhibition of human cancer-cell proliferation.

Design, synthesis, antiviral, and cytostatic evaluation of novel isoxazolidine analogues of C-nucleotides

5-Aryl-2-methylisoxazolidin-3-yl-3-phosphonates have been synthesised from N-methyl-C-diethoxyphosphorylnitrone and vinyl aryls in good yields. Isoxazolidine phosphonates obtained herein were evaluated for activity against a broad range of DNA and RNA viruses. None of the compounds were endowed with antiviral activity nor cytostatic activity at 100 to 250 μM concentrations.

An intermolecular C–H functionalization method for the synthesis of 3-hydroxy-2-oxindoles

An intermolecular C–H functionalization with a denitrosation-triggered cyclization method is developed for the synthesis of 3-hydroxy-2-oxindoles.

Cu(II)-promoted transformations of α-thienylcarbinols into spirothienooxindoles: regioselective halogenation of dienyl sulfethers containing electron-rich aryl rings

Under the promotion of Cu(II) salts, the α-thienylcarbinols with an N-phenyl carbonyl group at the other α-position are converted into three different ranges of spirothienooxindoles involving dearomatizing Friedel-Crafts reaction. In addition, the unprecedented regioselective CuX(2)-mediated C-H functionalization/halogenation of dienyl sulfether containing electron-rich aryl rings is presented.

Enantioselective and regioselective indium(III)-catalyzed addition of pyrroles to isatins

The indium(III)-catalyzed enantioselective and regioselective addition of pyrroles to isatins is described. The effects of metal and solvent on the reactivity and selectivity are compared and discussed, demonstrating that the indium(III)-indapybox complex provides the most effective catalyst. A case of divergent reactivity between pyrroles and indoles is presented.

Enantioselective Pictet-Spengler Reactions of Isatins for the Synthesis of Spiroindolones

The condensation cyclization between isatins and 5-methoxy tryptamine catalyzed by chiral phosphoric acids provides spirooxindole tetrahydro-β-carboline products in excellent yields (up to 99%) and enantioselectivity (up to 98:2 er). A comparison of catalysts provides insight for the substrate scope and factors responsible for efficient catalytic activity and selectivity in the spirocyclization. Chiral phosphoric acids with different 3,3'-substitution on the binaphthyl system and opposite axial chirality afford the spiroindolone product with the same absolute configuration.

Synthesis, biological evaluation and molecular modeling studies of N-aryl-2-arylthioacetamides as non-nucleoside HIV-1 reverse transcriptase inhibitors

A series of N-aryl-2-arylthioacetamide derivatives (2-4) designed as non-nucleoside reverse transcriptase inhibitors was synthesized and evaluated for their inhibitory activity against HIV-1 (IIIB) replication in MT-4 cell cultures. The compounds 2-4 were performed by the reaction of thiols and 2-chloro-N-substituted-acetamides and active in the lower micromolar concentration (1.25-20.83 μM). The studies of structure-activity relationship suggested that 1H-benzo[d]imidazole ring at arylthio moiety strongly improved the anti-HIV activity and consistent with the experimental data. The results of molecular modeling and docking within the RT non-nucleoside binding site using AutoDock confirmed that the 3 series, similar to other non-nucleoside reverse transcriptase inhibitors such as N-(5-chloro-2-pyridinyl)-N'-[2-(4-ethoxy-3-fluoro-2-pyridinyl)ethyl]-thiourea (PETT), was assumed in a butterfly-like conformation and helped to rationalize some SARs and the biological activity data.

Asymmetric construction of quaternary stereocenters by direct organocatalytic amination of 3-substituted oxindoles

Quinidine derivative (QD)(2)PYR was found to catalyze the asymmetric direct amination of unprotected prochiral 3-oxindole with DIAD to construct quaternary stereocenters at the C3 position with excellent enantioselectivity.