Synthesis of spiroindenyl-2-oxindoles by montmorillonite K-10-catalyzed tandem Friedel-Crafts alkenylation/hydroarylation of propargylic alcohols with sterically hindered and electron-rich arenes

Synthesis of Cyclopentadiindolyl Spirooxindoles via Palladium‐catalyzed Intramolecular Oxidative Indole‐Indole Coupling Reaction

“…Thus, tremendous efforts have been devoted to development of efficient protocols to access these important motifs over the past years . Recently, we reported the synthesis of various spirooxindoles including spiroindeno[1,2‐ b ]indolyloxindoles . The spiroindeno[1,2‐ b ]indolyloxindoles were synthesized from isatin and 2‐arylindole in the presence of TiCl 4 via sequential inter‐ and intramolecular Friedel‐Crafts reactions, as shown in Scheme .…”

“…Spirooxindoles exist in a huge number of natural substances and pharmaceutically interesting compounds . Thus, tremendous efforts have been devoted to development of efficient protocols to access these important motifs over the past years . Recently, we reported the synthesis of various spirooxindoles including spiroindeno[1,2‐ b ]indolyloxindoles .…”

“…The oxidative coupling reaction of NH derivative 1n failed, as we 2h and other groups have already observed …”

Synthesis of Spiroindenyl-2-Oxindoles through Palladium-Catalyzed Spirocyclization of 2-Bromoarylamides and Vinyl Bromides

“…On the other hand, spiroindenes have also gained considerable interest in medicinal chemistry [8][9][10][11][12][13]. The investigation of biological and pharmaceutical properties of spiroindenyl-2-oxindoles that contain both spiro-bridged indene and oxindole moieties is highly intriguing [14,15]. To achieve this, it is essential to develop efficient synthetic methods for the analysis of compounds of such a type.…”

“…To achieve this, it is essential to develop efficient synthetic methods for the analysis of compounds of such a type. Currently, the reactions for the synthesis of spiroindenyl-2-oxindoles are rare, and the majority of them rely on the use of 3-substituted indoles as the starting materials (Figure 1a-f) [14][15][16][17][18][19]. It should be noted that Desrosiers and coworkers reported an elegant synthetic approach for spiroindenyl-2-oxindoles through nickel-catalyzed intramolecular Heck cyclization (Figure 1g) [20,21].…”