I₂–TBHP-Catalyzed Oxidative Cross-Coupling of N-Sulfonyl Hydrazones and Isocyanides to 5-Aminopyrazoles

Abstract

I2-TBHP-catalyzed oxidative cross coupling of N-sulfonyl hydrazones with isocyanides has been realized for the synthesis of 5-aminopyrazoles through formal [4 + 1] annulation via in situ azoalkene formation. Notable features are the metal/alkyne-free strategy, C-C and C-N bond formation, atom economy, catalytic I2, broad functional group tolerance, good reaction yields, shorter time, and also applicability to one-pot methodology.

Denitrogenative Pd/Cu‐catalyzed Suzuki‐type Cross‐coupling of Aryltrifluoroborates with Arylhydrazine Hydrochlorides in Water under Room Temperature

“…As a special synthons containing C(sp 2 )‐N bond, arylhydrazines are used as organic synthesis blocks due to their low cost, high reactivity and easy availability, has attracted a growing interest of chemists due to its versatility by denitrogenation via transition‐metal catalyzed C–N activation. In cross‐coupling arylation.…”

Luxury of N‐Tosylhydrazones in Transition‐Metal‐Free Transformations

“…Shortly afterwards, another example of this type of oxidative cross‐coupling has been explored by the research group of Wang by employing the I 2 and TBHP catalytic system (Scheme ) . This method provided aminopyrazoles 141 in very good yields and features a broad scope with a high functional group tolerance.…”

Green One-pot Synthesis of Novel Polysubstituted Pyrazole Derivatives as Potential Antimicrobial Agents

“…[14][15][16][17] In this regard, a solution of the appropriate triethylamine in 1,4-dioxane efficiently catalysed synthesis of pyridine, thiophene and 4H-pyrane Similar procedures were designed to prepare pyrazole derivatives. [19][20][21][22][23][24] Most of these methods include simultaneous or multistep reaction of aldehyde, hydrazine and active methylene compounds under different conditions. [25][26][27][28][29] Recently, deep eutectic solvents (DESs) were widely applied as eco-friendly media or efficient catalysts in organic synthesis especially for the preparation of pyrazoles.…”