Indole 3-alkylation/vinylation under catalysis of the guanidinium ionic liquids

A novel domino protocol for three-component synthesis of new dibenzo[e,g]indoles: flexible intramolecular charge transfers

New and electronically interesting 2-aryl-3-nitrodibenzo[e,g]indoles were synthesized effectively via a hitherto unreported three-component domino reaction under catalysis of a superparamagnetic nano-composite.

Synthesis of Bis(indolyl)methanes Using Hyper-Cross-Linked Polyaromatic Spheres Decorated with Bromomethyl Groups as Efficient and Recyclable Catalysts

Highly uniform and hyper-cross-linked polyphenanthrene and polypyrene microspheres were synthesized by Friedel-Crafts bromomethylation of phenanthrene (Phn) and pyrene (Py) in the presence of zinc bromide as a catalyst, followed by self-polymerization of bromomethylated Phn and Py. The resultant 3-D carbon microspheres consisting of micro-, meso-, and macropores bear peripheral unreacted bromomethyl groups, which are directly utilized as catalysts to efficiently promote the electrophilic substitution reaction of indoles with aldehydes to yield a variety of bis(indolyl)methanes. The important features of this catalysis are easy catalyst synthesis, high product yields, environmental benignity, short reaction time, broad substrate scope, use of nontoxic solvents, and recyclability.

Efficient catalytic application of a binary ionic liquid mixture in the synthesis of novel spiro[4H-pyridine-oxindoles]

Novel pyrazole-fused spiro[4H-pyridine-oxindoles] were synthesized under the catalysis of the binary ionic liquid mixture [1,1,3,3-tetramethylguanidinium chloride][1-methylimidazolium-3-sulfonate] in solvent-free conditions.

Synthesis, characterization and photophysical properties of some 3,3′-bisindolyl(aryl)methanes

A series of 3,3′-bisindolyl(aryl)methanes were synthesized and fully characterized by a combination of¹H and¹³C NMR spectroscopy and in one case using X-ray crystallography.

Choline chloride based eutectic solvents: direct C-3 alkenylation/alkylation of indoles with 1,3-dicarbonyl compounds

C-3 alkenylation/alkylation of indoles depends on the position of the substituent on the indole used in the reaction.

Friedel-Crafts arylation reactions of N-sulfonyl aldimines or sulfonamidesulfones with electron-rich arenes catalyzed by FeCl3 x 6 H2O: synthesis of triarylmethanes and bis-heteroarylarylmethanes

The FeCl(3) x 6H(2)O-catalyzed Friedel-Crafts arylation reactions of N-sulfonyl aldimines or sulfonamidesulfones with electron-rich arenes and heteroarenes, which lead to the formation of triarylmethanes and bis-heteroarylarylmethanes, are developed. The use of mild reaction conditions, low catalytic loading, high yield, and single step synthesis are the advantages of the present procedure.

Synthesis of symmetrical and unsymmetrical 3,3-di(indolyl)indolin-2-ones under controlled catalysis of ionic liquids

Three ionic liquids, [BMIM][BF₄] doped with 60 mol % of LiCl ([BMIM][BF₄]–LiCl), N,N,N,N-tetramethylguanidinium trifluoroacetate (TMGT), and N,N,N,N-tetramethylguanidinium triflate (TMGT_f) were found useful as catalyst solvents for controlled 3-indolylation of isatins. Our investigation revealed that the reaction between isatin and indoles in [BMIM][BF₄]–LiCl or TMGT_f media stops at the step of addition of the two components providing 3-indolyl-3-hydroxyindolin-2-ones while the ionic liquid TMGT runs the reaction further through accompanying Friedel–Crafts substitution to afford symmetrical 3,3-di(indol-3-yl)indolin-2-ones. To take advantage of the difference between the effects of these ionic liquids on the reaction progress, we planned a two-step protocol for the efficient synthesis of unsymmetrical 3,3-di(indol-3-yl)indolin-2-ones.