Synthesis of some novel and complex thiopyrano indole derivatives from simple oxindole via intramolecular domino hetero Diels–Alder reactions

Base-mediated cascade synthesis of indole diolefins: a route to spiro[cyclopentene-indole]thiones and thiepino[2,3-b]indoles

Base-mediated cascade reactions of 3-hydroxymethyl-3-propenylindole-2-thiones afforded diolefins and involved deformylation, thioenolate alkylation and the thio-Claisen rearrangement. Subsequent ring-closing metathesis reactions of the diolefins furnished 3-spiro[cyclopentene-indole]-2-thiones or thiepino[2,3-b]indoles.

Synthesis of tetrahydrothiopyrano[2,3-b]indoles via [3+3] annulation of nitroallylic acetates with indoline-2-thiones

[3+3] annulation of 1,3-binucleophilic indolin-2-thione with 1,3-bielectrophilic nitroallylic acetate via an S_N2-reaction-6-endo-trig cyclization takes place with high regio- and stereoselectivity to afford tetrahydrothiopyranoindoles.

Access to thiopyrano[2,3-b]indole via tertiary amine-catalyzed formal (3+3) annulations of β′-acetoxy allenoates with indoline-2-thiones

Amine-catalyzed formal (3+3) annulations of β′-acetoxy allenoates with indoline-2-thiones are described, which provide facile access to thiopyrano[2,3-b]indole.

Copper-catalyzed tandem arylation–cyclization of 2-alkynylaryl isothiocyanates with diaryliodonium salts: an efficient synthesis of thiochromeno[2,3-b]indoles

A Cu-catalyzed arylation–cyclization approach is developed for the synthesis of thiochromeno[2,3-b]indoles through the S-arylation, 5-endo-trig cyclization, and Friedel–Crafts-type cyclization sequence.

Synthesis of indole-annulated sulfur heterocycles using copper-catalysed C–N coupling and palladium-catalysed direct arylation

A simple and efficient method for the synthesis of biologically relevant 5H-benzo[4,5][1,3]thiazino[3,2-a]indoles and 5,7-dihydroisothiochromeno[3,4-b]indoles has been developed via intramolecular copper catalysed Ullmann-type C–N coupling and palladium catalysed direct arylation.

Microwave-Assisted Synthesis and Antibacterial Activity of Unsymmetrical Indolyl/Aryl Bis-Thiosemicarbazones

A series of nine novel unsymmetrical bis-thiosemicarbazones were prepared in high yield by condensation of aromatic aldehyde thiosemicarbazones with indole-3-carboxaldehyde using microwave irradiation. The structures of the new compounds were characterised. Six of the compounds displayed varying levels of antibacterial activity against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus.