https://libjncir.jncasr.ac.in/xmlui/handle/10572/1490 2026-04-04T05:35:05Z 2026-04-04T05:35:05Z Kumar, S. Vijay Saraiah, B. Parameshwarappa, G. Ila, H. Verma, Girijesh K. https://libjncir.jncasr.ac.in/xmlui/handle/10572/2490 2017-02-21T10:24:42Z 2014-01-01T00:00:00Z

Synthesis of N-Functionalized/NH-Multisubstituted Indoles, Thienopyrroles, Pyrroloindoles, and Pyrazolopyrroles via Sequential One-Pot Base-Mediated and Copper-Catalyzed Inter- and Intramolecular Amination of 2-[2-Bromo(het)aryl]-3-(het)aryl-3-(methylthio)acrylonitriles Kumar, S. Vijay; Saraiah, B.; Parameshwarappa, G.; Ila, H.; Verma, Girijesh K. A novel, efficient route to substituted 1-N-(het)aryl/NH-2-(het)aryl-3-cyanoindoles and related pyrrolo-fused heterocycles such as thienopyrroles, pyrroloindoles, and pyrazolopyrroles has been reported. The overall protocol involves sequential cycloamination of readily available 2-[2-bromo(het)aryl]-3-(het)aryl-3-(methylthio)acrylonitrile precursors with primary amines or amides via two key C-N bond-forming processes, one base-mediated intermolecular and the other Cu-catalyzed intramolecular arylamination leading to N(1)-C(2) and N(1)-C(7a) bond formation, respectively, in a two-step one-pot procedure. Restricted Access

2014-01-01T00:00:00Z Yugandar, S. Konda, S. Parameshwarappa, G. Ila, H. https://libjncir.jncasr.ac.in/xmlui/handle/10572/2205 2017-02-21T10:22:46Z 2016-01-01T00:00:00Z

One-Pot Synthesis of 2,4,5-Trisubstituted Imidazoles via [2+2+1] Cycloannulation of 1,3-Bishet(aryl)-monothio-1,3-diketones, alpha-Substituted Methylamines and Sodium Nitrite through alpha-Nitrosation of Enaminones Yugandar, S.; Konda, S.; Parameshwarappa, G.; Ila, H. An efficient one-pot synthesis of a series of diversely functionalized trisubstituted 4(5)het(aroyl)-2,5(4)-het(aryl)/alkylimidazoles from readily available 1,3-bishet(aryl)monothio-1,3-diketones has been reported. This novel sequential one-pot, three step protocol, wherein three new carbon nitrogen bonds are formed in contiguous fashion, involves in situ generation of enaminones by reaction of monothio-1,3-diketones with alpha-substituted methylamines, followed by their alpha-nitrosation with sodium nitrite and subsequent base mediated intramolecular heterocyclization of the resulting alpha-hydroxyiminoimines to trisubstituted imidazoles in high yields under mild conditions. These newly prepared 4(5)-het(aroyl)-5(4)-het(aryl)/alkylimidazoles are shown to exist as tautomeric mixture, however, their subsequent alkylation with methyl iodide in the presence of potassium carbonate affords 1-N-methy-2,5-bishet(aryl)-4-het(aroyl)imidazoles in highly regioselective fashion in most of the cases. Synthesis of few 4(5)-(2-hydroxyphenyl)-2,5(4)-substituted imidazoles, which are known to be good coordinating ligands, has also been reported. A probable mechanism for the formation of these imidazoles from hydroxyiminoimine intermediates has also been suggested. Restricted Access

2016-01-01T00:00:00Z Yugandar, Somaraju Konda, Saidulu Ila, Hiriyakkanavar https://libjncir.jncasr.ac.in/xmlui/handle/10572/2204 2017-02-21T10:23:19Z 2016-01-01T00:00:00Z

Amine Directed Pd(II)-Catalyzed C-H Activation-Intramolecular Amination of N-Het(aryl)/Acyl Enaminonitriles and Enaminones: An Approach towards Multisubstituted Indoles and Heterofused Pyrroles Yugandar, Somaraju; Konda, Saidulu; Ila, Hiriyakkanavar An efficient route to multisubstituted indoles has been developed through intramolecular oxidative C-H activation-amination of readily available 2-(het)aryl-3-(het)aryl/alkyl-3-(het)aryl/acylaminoacrylonitrile/enaminone precursors in the presence of either palladium acetate/cupric acetate catalytic system under oxygen atmosphere or palladium acetate/silver carbonate in the presence of pivalic acid as additive. The method is compatible with a diverse range of substituents on the aryl ring as well as at the 2- and 3-positions of the indole ring. The versatility of this method was further demonstrated by elaborating it for the synthesis of heterofused pyrroles such as thieno[2,3-b]pyrroles, thieno[3,2-b]pyrroles, pyrrolo[2,3-b]indoles, and pyrrolo[2,3-b]pyridines in good yields. Probable mechanisms for the formation of these indoles have been suggested. Open Access (Accepted Manuscript); Restricted Access (Publisher's PDF)

2016-01-01T00:00:00Z Acharya, Anand Parameshwarappa, G. Saraiah, B. Ila, H. https://libjncir.jncasr.ac.in/xmlui/handle/10572/2006 2017-02-21T10:21:50Z 2015-01-01T00:00:00Z

Sequential One-Pot Synthesis of Tri- and Tetrasubstituted Thiophenes and Fluorescent Push Pull Thiophene Acrylates Involving (Het)aryl Dithioesters as Thiocarbonyl Precursors Acharya, Anand; Parameshwarappa, G.; Saraiah, B.; Ila, H. An efficient, one-pot three component synthesis of highly functionalized tri- and tetrasubstituted thiophenes has been reported involving (het)aryl dithioesters as thiocarbonyl precursors. Thus, sequential base mediated condensation of readily available (het)aryl active methylene ketones with (het)aryl dithioesters followed by S-alkylation of the resulting enethiolate salts with activated halomethylene compounds and concurrent intramolecular aldol-type condensation of S-alkylated compounds affords substituted thiophenes in excellent yields. The methodology has also been extended for the synthesis of highly fluorescent push-pull substituted thiophene-5-acrylates by using bromocrotonate as the activated methylene alkylating agent. Restricted access

2015-01-01T00:00:00Z