Synthesis of Pyrido[2,3-b]indole Derivatives via Diels–Alder Reactions of 2- and 3-Vinylpyrrolo[2,3-b]pyridines

Bismuth nitrate-promoted disproportionative condensation of indoles with cyclohexanone: a new-type azafulvenium reactivity of indole

The bismuth nitrate-promoted disproportionative condensation of indoles with cyclohexanone in one pot, to yield C3-cyclohexyl substituted indoles and 1,3-di(1H-indol-3-yl)benzene derivatives is reported for the first time.

Organometallic methods for the synthesis and functionalization of azaindoles

Azaindoles (also called pyrrolopyridines) constitute essential subunits in many pharmaceutically important compounds. The synthesis of azaindoles has been a great synthetic challenge for chemists. Many classical methods for indole synthesis (such as Fischer and Madelung cyclizations) often cannot be effectively applied to the synthesis of the corresponding azaindoles. In recent years, advances in organometallic chemistry have enabled a number of novel and efficient methodologies for azaindole formation as well as for the further functionalization of azaindole templates. In this tutorial review, we have surveyed the recent development of organometallic chemistry-based methods for azaindole synthesis.

Synthesis of New 2-Vinylation Products of Indole via a Michael-Type Addition Reaction with Dimethyl Acetylenedicarboxylate and Their Diels−Alder Reactivity as Precursors of New Carbazoles

Reaction of 4,7-dihydroindole and dimethyl acetylenedicarboxylate provided a convenient route to functionalized 2-vinylindoles. Diels-Alder reactions of the 2-vinylindoles with naphthoquinone, p-benzoquinone, 1,2-dicyano-4,5-dichloroquinone, N-phenyltriazolinedione, and tetracyanoethylene were investigated to give [c]annelated 1,2-dihydro, 1,2,3,4-tetrahydro, and fully aromatized carbazoles. The structure and formation mechanism of both 2-vinylindoles and their cycloadduct are discussed.

Synthesis and anticancer activity of new pyrrolocarbazoles and pyrrolo-β-carbolines

'Bended' 1, 3 or 'linear' 2 pyrrolidino-fused (aza)carbazoles were prepared and screened towards a few cancer-related targets. Whereas 'bended' derivatives 1 and 3 proved to be weakly toxic, several members of the 'linear' family strongly interact with DNA, especially derivative 28a.

Synthesis, cytotoxicity, DNA interaction and topoisomerase II inhibition properties of tetrahydropyrrolo[3,4-a]carbazole-1,3-dione and tetrahydropyrido-[3,2-b]pyrrolo[3,4-g]indole-1,3-dione derivatives

Three tetrahydropyrrolo[3,4-a]carbazole-1,3-diones (6--8) and two tetrahydropyrido[3,2-b]pyrrolo[3,4-g]indole-1,3-diones (11--12) have been synthesized. Their interaction with DNA was probed by absorption and thermal melting studies. Compounds 8 and 12 both equipped with a hydroxyethyl-aminoethyl side-chain demonstrated higher affinities for poly(dA-dT)(2) than compounds 6, 7 and 11 bearing a dimethylaminoethyl side-chain. Circular and electric linear dichroism measurements showed that all five drugs behave as typical DNA intercalating agents. A plasmid cleavage assay was used to evaluate the capacity of the drugs to inhibit human topoisomerase II. Compounds 8 and 12 which bind strongly to DNA were found to stabilize DNA-topoisomerase II covalent complexes but their topoisomerase II inhibitory properties do not correlate with their cytotoxic potential. Compounds 6 and 7 are essentially inactive whereas compounds 8, 11 and 12 exhibit a high toxicity to P388 murine leukemia cells and provoke a marked accumulation in the G2/M phase of the cell cycle. These compounds form a new class of DNA-targeted antitumor agents.