1383663-65-7Relevant academic research and scientific papers
Enantioselective Organocatalytic Michael Addition to Unsaturated Indolyl Ketones
Trubitsoìn, Dmitri,Martoìnova, Jevgenija,Kudrjasìova, Marina,Erkman, Kristin,Jaìrving, Ivar,Kanger, Toìnis
, p. 1820 - 1824 (2021)
An efficient enantioselective organocatalytic method for the synthesis of N-alkylated indoles with α-branched alkyl substituents from the corresponding unsaturated indolyl ketones via a Michael addition has been developed. The resulting products were obtained in high enantioselectivities and in good yields. Various nucleophiles (nitroalkanes, malononitrile, malonic esters) can be used. The substitution pattern of the indole ring had no significant impact on the reaction outcome. Both electron-withdrawing and electron-donating substituents in any position of the heteroaromatic ring were well-tolerated.
Base-mediated selective synthesis of diversely substituted N-heterocyclic enamines and enaminones by the hydroamination of alkynes
Joshi, Megha,Patel, Monika,Tiwari, Rakesh,Verma, Akhilesh K.
, p. 5633 - 5645 (2012/08/07)
Regio- and stereoselective alkynylation of various N-heterocycles 1a-l using potassium and cesium salts in DMSO is described. Terminal alkynes 2a-k and internal alkynes 4a-f provided the kinetically stable Z-enamines 3a-l and 5a-i in good to excellent yields using KOH at 120 °C. Addition of heterocyclic amines to 1,3- and 1,4-diethynylbenzene 6a-b provided the mixture of E/Z isomers with KOH; however, with Cs2CO3 selectively Z-isomers 7ab-db were obtained by the hydroamination at one triple bond. This developed methodology also provides an easy and novel access for the synthesis of enaminones 10a-c. The detailed work also supports the formation of cis-isomer by preferential addition of o-haloarylalkynes followed by intramolecular C2 arylation in the copper-catalyzed tandem synthesis of indolo and pyrrolo[2,1-a]isoquinolines.
