DABCO-Catalyzed Multicomponent Reaction for Synthesis of Benzo[a]carbazoles

Abstract

DABCO (1,octane) catalyzed a multicomponent reaction using the starting precursor 2,3,4,9-tetrahydro-1H-carbazol-1-one, malononitrile, and aromatic/heteroaromatic aldehyde.

The versatility of DABCO as a reagent in organic synthesis: a review

“…Table 15 shows the variation of yield of spiropyran indolo quinazolines using DABCO with the change in the substituents. The synthesis of a series of trisubstituted pyridazines (73) in a one-pot three-component synthesis in aqueous medium employing propiophenones (71), arylglyoxal monohydrates (72) and hydrazine hydrates. DABCO acts as a base in the knoevenagel condensation of propiophenones with arylglyoxals, resulting in the synthesis of 1,4-dicarbonyl compounds which then react with hydrazine hydrate to produce 3,6-diaryl-4methylpyridazines (Scheme 25).…”

“…The ability of benzo[a]carbazole ring systems to display substantial anticancer activity against leukaemia, renal tumour, colon cancer and malignant melanoma tumour cell lines as well as kinase inhibitory properties makes them of great interest. 70,71 Owing to their DNA intercelative binding capabilities, benzo[a] carbazoles which have an aromatic ring bonded to the a-face of the carbazole nucleus, are promising cancer therapeutic possibilities. 71,72 Several derivatives of 2,3,4,9-tetrahydro-1H-carbazol-1-one (77), a synthetic precursor of carbazole have recently garnered a wide interest owing to their potential as fluorophores.…”

“…70,71 Owing to their DNA intercelative binding capabilities, benzo[a] carbazoles which have an aromatic ring bonded to the a-face of the carbazole nucleus, are promising cancer therapeutic possibilities. 71,72 Several derivatives of 2,3,4,9-tetrahydro-1H-carbazol-1-one (77), a synthetic precursor of carbazole have recently garnered a wide interest owing to their potential as fluorophores. [72][73][74][75][76][77][78][79][80][81][82][83][84] Indumathi et al used derivatives of 2,3,4,9-tetrahydro-1H-carbazol-1-one (77), malononitrile and aromatic/heteroaromatic aldehyde in a DABCO catalyzed multicomponent reaction to produce benzo[a]carbazoles (79) (Scheme 27).…”

Synthesis and photophysical properties of fluorescent 8,9‐diarylbenzo[def]carbazoles

“…In 1965, Chakraborty et al reported the isolation and antibiotic properties of murrayanine from Murraya koenigii Spreng [2,3]. Since then, exploration of the syntheses and properties of carbazole derivatives has become intense interests among chemists and biologists [4][5][6][7][8][9][10][11][12]. Furthermore, carbazole is an important and privileged scaffold in electronic materials such as organic light-emitting diodes and photoconducting polymers [13][14][15][16][17].…”

One-Pot Access to Benzo[a]carbazoles via Palladium(II)-Catalyzed Hetero- and Carboannulations

“…A scrutiny of the literature indicated that a number of synthetic methodologies have been established for benzo­[ a ]­carbazoles in the past decades using classical reactions like thermal and photochemical cyclizations, pericyclic reactions, , and Fischer indole synthesis. ,, In addition, a few reaction strategies using conventional reagents have also been demonstrated. , Most of these reactions, however, suffer from the need to synthesize complex starting materials or use harsh reaction conditions, or are multistep ones with low yields. To overcome this lacuna, some metal-catalyzed reactions employing prefunctionalized indole derivatives as substrates have recently been demonstrated .…”