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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.

An atom-economical diastereoselective synthesis of indenodithiepines and indenodithiocines has been developed via a domino reaction of propargylic alcohols and dithioacetals in the presence of InCl3 as a catalyst. A range of functionalized dithiepines and dithiocines, fused to the indene ring, were obtained in good to excellent yields under mild conditions.

A highly diastereoselective tandem ring-enlargement and aldol condensation process involving multicomponent reactions of ethereal tricyclooxonium ylide intermediate with alcohols, mono- or dialdehydes in the presence of titanium(iv) isopropoxide is described to furnish alkoxyoctahydro-1,4-benzodioxocin-6(5H)-one ring systems.

The reverse regio- and diastereoselectivities are observed between the reactions involving 5- and 6-membered-ring cyclic carbonyl ylide dipoles with alpha-methylene ketones. A mild catalytic route to synthesize spirocyclic systems with high regio-, chemo- and diastereoselectivities is described.

Simply, trapping the intermediate isomünchnone 1,3-dipoles by the external oxygen nucleophiles resulted in new heterocyclic systems and the use of diols led to the formation of four carbon-oxygen bonds in a single operation which eventually delivered bis(2,3-fused perhydrooxazol-4-one) systems.

Facile regiospecific intermolecular C-H insertion reactions of cyclic rhodium carbenoids have been achieved using diazo carbonyl compounds 1 and indole or N-substituted indoles to afford 1,3-dihydro-1'H-[3,3']biindolyl-2-ones, 3a-o in an excellent yield.