The stereoselective synthesis of highly functionalized tertiary 3-aminoindoles/anilines or dihydropyrroles from C-(3-indolyl)-N-aryl and C,N-diaryl nitrones

We report on the novel properties of nitrones including their transformations via reactions with sodium malonates to give functionalized stereodefined derivatives of tertiary 3-aminoindoles or anilines, as well as fully-substituted dihydropyrroles. The outcome of the reactions is dependent mainly upon the nature of the starting C-nitrone substituent and solvent used. The formation of a new carbon-nitrogen bond in the obtained amines occurs via a nucleophilic 1,2-aryl/3-indolyl shift from C to the adjacent nitrogen.

The reaction of C-(3-indolyl)/aryl-N-aryl nitrones and sodium malonates affords either derivatives of tertiary amines-salts of (2Z)-3-[(1H-(3-indolyl)/aryl)amino]-2-(alkoxycarbonyl)acrylic acid and (2E)-3-(diarylamino)acrylates, respectively, or fully-substituted dihydropyrroles, dimethyl 1-aryl-5-aryl′/hetaryl-3-hydroxy-2,5-dihydro-1H-pyrrole-2,4-dicarboxylates depending on the nature of the starting C-nitrone substituent.