l-Proline catalyzed stereoselective synthesis of (E)-methyl-α-indol-2-yl-β-aryl/alkyl acrylates: easy access to substituted carbazoles, γ-carbolines and prenostodione
作者:Soumen Biswas、Pradeep Kumar Jaiswal、Shivendra Singh、Shaikh M. Mobin、Sampak Samanta
DOI:10.1039/c3ob41573b
日期:——
A simple, mild and robust method for the stereoselective synthesis of (E)-methyl α-(3-formyl-1H-indol-2-yl)-β-aryl/alkyl-substituted acrylates via a condensation reaction of methyl 2-(3-formyl-1H-indol-2-yl)acetate with several alkyl or aryl aldehydes using L-proline (25 mol%) as a catalyst is presented for the first time. In addition, completely metal free based high yielding methods for the syntheses
procedure for the direct synthesis of highly functionalized 1-methoxycarbonyl-2-aryl/alkyl-3-nitro-9H-carbazoles has been achieved in water medium via a one-pot domino Michael–Henry/aromatization reaction of methyl 2-(3-formyl-1H-indol-2-yl)acetates with aryl/alky-substituted β-nitroolefins under air using DABCO (30 mol%) as an organocatalyst. In addition, the bench scale synthesis can be performed without