Direct Arylations of 2H-Indazoles On Water

Abstract

The efficient palladium-catalyzed synthesis of a range of substituted 2H-Indazoles via C-H arylation is reported. Reactions are performed on water and provide a direct and mild route toward 2,3-diaryl indazoles of widespread biological significance.

Synthesis of 2H-Indazoles by the [3 + 2] Dipolar Cycloaddition of Sydnones with Arynes

“…The 1 H NMR spectral data now matched the literature values. 18 Similarly, compound 3id' , the 7-MeO isomer from the reaction of 1i and 2d , could be isolated pure in about a 42% yield.…”

Direct Synthesis of Pyrazolo[5,1‐a]isoindoles via Intramolecular Palladium‐Catalyzed CH Bond Activation

“…[19] Both electron-donating and electron-withdrawing substituents on the bromoarene were tolerated, providing the desired products in good yields (entries 7-9). Sterically hindered bromoarene 1p was also a good substrate for cyclization and provided 3,4-dimethyl-substituted pyrazoloisoindole 3k in 97% yield (entry 10).…”

Regioselective zincation of indazoles using TMP2Zn and Negishi cross-coupling with aryl and heteroaryl iodides

“…Also the direct arylation 8 of 2H-indazoles as well as the use of 3-iodoindazoles in Suzuki- 9 or Stille 10 cross-couplings is known. However, the direct metalation and transition metal catalyzed arylation of 1H-indazoles has not been reported.…”