Condensation of Indoline with Some 1,2‐ and 1,3‐Diketones

Abstract

Bismuth nitrate catalyzed condensation reactions of indoline with 1,2‐ and 1,3‐diketones were investigated and were reported to proceed via different reaction pathways with the involvement of one or two of the carbonyl groups. While the reaction of indoline with cyclohexane‐1,3‐dione (4) gave solely condensation product, the reaction between the acetylacetone (5) and indoline provided N‐acetyl indoline as single products on retro‐aldol process. In contrast to 1,3‐diketones, the reaction with benzil (17) was performed under difficult conditions and proceeded to give secondary products.

Chemistry and Properties of Indolocarbazoles

“…208 In a study of rather limited scope, 5,12-dihydro-6,7-diphenylindolo[3,2-a]carbazole has been reported as a product in 71% yield from the reaction of benzil and indole in the presence of catalytic amounts of Bi(NO 3 ) 3 •5H 2 O in acetonitrile at 120 °C, whereas a similar reaction involving indoline instead of indole gave the same product in 40% yield with coformation of three other components. 209 In contrast to ring synthesis, the reactivity and modification of indolo [3,2-a]carbazoles are scantily studied topics. Apart from some examples included in the text above, which all can be considered as standard transformations, a study reporting selective palladium-catalyzed N-arylation is available.…”

“… An additional application of the annulation method mentioned above, involving 1-(1 H -indol-3-yl)-2-phenylethane-1,2-diones and indoles as the reaction components, furnished a set of 5,12-dihydro-6-(1 H -indol-3-yl)-7-phenylindolo­[3,2- a ]­carbazole derivatives (four examples) in modest yields . In a study of rather limited scope, 5,12-dihydro-6,7-diphenylindolo­[3,2- a ]­carbazole has been reported as a product in 71% yield from the reaction of benzil and indole in the presence of catalytic amounts of Bi­(NO 3 ) 3 ·5H 2 O in acetonitrile at 120 °C, whereas a similar reaction involving indoline instead of indole gave the same product in 40% yield with coformation of three other components …”

The synthesis of new oxindoles as analogs of natural product 3,3′-bis(indolyl)oxindole and in vitro evaluation of the enzyme activity of G6PD and 6PGD

“…Figure S2 13. C NMR (100 MHz) spectra of 3-(4,7-dihydro-1H-indol-2-yl)-3-hydroxyindolin-2-one (5) (DMSO-d6).…”

The synthesis of N‐benzoylindoles as inhibitors of rat erythrocyte glucose‐6‐phosphate dehydrogenase and 6‐phosphogluconate dehydrogenase

“…Therefore, a great deal of attention has been given to develop effective, facile, and innovative synthetic strategies for the development of the indole chemistry. [16][17][18][19][20] The indole exhibits reactivity at the C-3 position against the electrophiles and generally forms the 3-substituent indole derivatives. An alternative method that utilizes indoline (4) for an easy and effective synthesis of N-substituted indoles was developed by Saracoglu and group.…”

“…An alternative method that utilizes indoline (4) for an easy and effective synthesis of N-substituted indoles was developed by Saracoglu and group. [16][17][18][19][20] The indole exhibits reactivity at the C-3 position against the electrophiles and generally forms the 3-substituent indole derivatives. Therefore, the synthesis of Nsubstituted indole derivatives, which form the main framework of many natural indole derivatives via reactions of indole, is quite difficult, and the reaction product is obtained with very low yields.…”