Rapid and Efficient Synthesis of 3,3-Di(1H-indol-3-yl)indolin-2-ones and 2,2-Di(1H-indol-3-yl)-2H-acenaphthen-1-ones Catalyzed by p-TSA

Abstract

All of the reagents were purchased from Aldrich-reagent and used without further purifications. 1 H NMR spectra and 13 C NMR spectra were recorded on a Bruker Advance III 500 MHz spectrometer and using DMSO-d 6 (500 MHz for 1 H or 125 MHz for 13 C, respectively) as solvent. Chemical shifts of 1 H and 13 C NMR spectra were expressed in δ values (ppm) downfield from tetramethylsilane. Microanalyses were taken on a VARIOX Elemental Analyzer. Mass spectra were carried out on VARIAN1200. IR spectra were obtained on a TENSOR 27 spectrometer. Melting points were recorded on microscope (SGW X-4) melting point apparatus. The reaction was monitored by TLC. Experimental details and characterizationGeneral procedure for preparation of oxindole derivatives 3a-3p and 5a-5e A mixture of the isatin 1 or acenaphthenequinone 4 (1 mmol), indole 2 (2 mmol), p-TSA (10 mol %), CH 2 Cl 2 (10 mL) was added to 50 mL flask and stirred at room temperature until the the completion of the reaction (Scheme 1, 2). Then the solid was filtered and washed with CH 2 Cl 2 (5 mL) and ethanol (5 mL) in turns, affording the product in excellent yields, which was recrystallized from ethanol to produce pure crystalline products. The products were identified by elemental analysis, MS, 1 H NMR, 13 C NMR, and IR spectra. Scheme 1. Preparation of product 3a-3p Scheme 2. Preparation of product 5a-5e Spectroscopic and characterization data 3,3-di(1H-indol-3-yl)indolin-2-one (3a): Yield: 92%; white solid; m. p. 318-320 (lit. [26]

Chemistry of trisindolines: natural occurrence, synthesis and bioactivity

“…p -Toluenesulfonic acid ( p -TSA) is a nontoxic, affordable, safe, and readily available catalyst used frequently in many organic transformations. 35 Yu et al (2014) prepared a series of trisindolines 3, 16, 23, 27 and 30–41 in 82–95% yields within 10–150 minutes employing 5 mol% p -TSA-catalyzed reaction of isatins and indoles in dichloromethane at room temperature ( Scheme 6 ). 35 Reactions of isatins bearing EDG afforded higher yields under shorter reaction time compared to reactions of isatins bearing EWG.…”

Silica-Coated Magnetic-Nanoparticle-Supported DABCO-Derived Acidic Ionic Liquid for the Efficient Synthesis of Bioactive 3,3-Di(indolyl)indolin-2-ones

“…In this context, numerous metal salts and complexes, such as Bi(OTf) 3 , 7 Zn(OTf) 2 , 8 Zr(salphen)Cl 2 , 9 FeCl 3 , 2 and (NH 4 ) 2 [Ce(NO 3 ) 6 ], 10 have produced the desired indolinones in good to excellent yields. A range of other acid catalysts such as p -toluenesulfonic acid, 11 sulfamic acid, 12 and Wells–Dawson-type tungstophosphoric heteropolyacid 13 have also been utilized to carry out the synthesis. However, most of the above methods are associated with one or more drawbacks, such as the use of exhaustible metal reserves, harsh and corrosive acids, tedious workup procedures, and unrecyclable catalysts.…”

MgCl2 catalyzed one-pot synthesis of 2-hydroxy-3-((5-methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)(phenyl)methyl)naphthalene-1,4-dione derivatives in EG

“…It is notable to mention here that after completion of the reaction, tautomerisation occurred in the pyrazolone rings of 5, which may exist in two tautomeric forms. Based on the X-ray crystal structure analyses in our previous work [18][19][20][21][22][23][24][25] and Tu's work 26 , it could be concluded that the desired products have two different structures: C=O form structure (Table 2, entries 5aa-5dc)…”

“…[11][12][13][14][15][16][17] It is promising that the integration of these two bioactive units into a single molecule may exhibit new or improved pharmacological properties.Considering the above points, and also in continuation of our interest on the synthesis of different kinds of heterocyclic compounds based on MCRs. [18][19][20][21][22][23][24][25] Herein we wish to report MgCl 2 as a low-toxic catalyst for one-pot synthesis of 2-hydroxy-3-((5-methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)(phenyl)methyl)naphthalene-1,4-dione…”