The facile synthesis of 2-bromoindoles via Cs2CO3-promoted intramolecular cyclization of 2-(gem-dibromovinyl)anilines under transition-metal-free conditions
C-Glycosides are metabolically stable mimics of natural O-glycosides and are expected to be useful tools for investigation of the biological functions of glycans. Here, we describe the synthesis of a series of aryl and vinyl C-glycosides by stereoinvertive sp3–sp2 cross-coupling reactions of 2-deoxyglycosyl boronic acid derivatives with aryl or vinyl halide, mediated by a photoredox/nickel dual catalytic
Microwave irradiated synthesis of 2-bromo(chloro)indoles via intramolecular cyclization of 2-(gem-dibromo(chloro)vinyl)anilines in the presence of TBAF under metal-free conditions
作者:Min Wang、Pinhua Li、Wei Chen、Lei Wang
DOI:10.1039/c4ra00603h
日期:——
2-Bromo(chloro)indoles were readily prepared through TBAF-promoted intramolecular cyclization of 2-(gem-dibromo(chloro)vinyl)anilines in excellent yields under metal-free and microwave irradiation conditions.
FeCl<sub>3</sub>-Promoted Annulation of 2-Haloindoles: Switchable Synthesis of Spirooxindole-chromeno[2,3-<i>b</i>]indoles and Spirooxindole-chromeno[3,2-<i>b</i>]indoles
Electrophilic indoles bearing a leaving group at C2 undergo C3-regioselective dearomative hydroaryloxylation and subsequent 1,2-tertiary alkyl migration/aromatization. This is the first ring-opening migration of the spiroindolenine intermediate formed by the C3 nucleophilic addition reaction. Various spiro-oxindole-chromeno[3,2-b]/[2,3-b]indoles were successfully synthesized in excellent yields (up
A mild and efficient synthesis of 2-bromoindoles by ligand-free CuI-catalyzed intramolecular cross-coupling of gem-dibromoolefins was developed. Reactions were carried out in toluene at room temperature and the corresponding 2-bromoindoles were obtained in excellent yields. (C) 2010 Elsevier Ltd. All rights reserved.
Base-Mediated Synthesis of 2-Bromobenzoheterocycles
A base-mediated cyclization to synthesize 2-bromobenzoheterocycles is reported. This transformation was demonstrated with 16 examples to access a broad range of brominated benzoheterocycles. Mechanistic studies support the reaction proceeds through a bromoalkyne, and revealed an exchangeable proton at C3 of the indole products.