Cu-Catalyzed tandem N-arylation of phthalhydrazides with cyclic iodoniums to yield dihydrobenzo[c]cinnolines

Abstract

<p>Cu-Catalyzed tandem <italic>N</italic>-arylation of dihydrazides with cyclic iodoniums to yield dihydrobenzo[<italic>c</italic>]cinnolines has been reported.</p>

Consequent Construction of C–C and C–N Bonds via Palladium-Catalyzed Dual C–H Activation: Synthesis of Benzo[c]cinnoline Derivatives

“…The desired product of benzo[c]cinnoline 7 was obtained in 90% yield (Scheme 2). 32,48 ■ CONCLUSIONS…”

“…Procedure for the Synthesis of Benzo[c]cinnoline (7). 48 Compound 3a (139 mg, 0.5 mmol) was dissolved in ethanol (2.5 mL, 0.2 M) with a stir bar in a test tube, followed by the dropwise addition of sodium hydroxide aqueous solution (5.0 M, 0.5 mL, 2.5 mmol). The resulting solution was heated at 70 °C for 10 h under an oxygen atmosphere.…”

Copper‐Catalyzed Selective N‐Arylation of Oxadiazolones by Diaryliodonium Salts

“…The electron-rich heterocycles can be arylated by iodonium salts in relatively mild conditions, [37][38][39][40] while electron-poor (especially cyclic amides and related compounds) require the addition of catalyst. [41][42][43][44][45][46] Also, the synthetic procedures for preparing diaryliodonium salts make available the versatile scope of these compounds with high yields from common laboratory reagents. [47][48][49][50][51][52][53][54] Nevertheless, the chemoselectivity of arylation of N,O-containing heterocycles presents a challenging task in hypervalent iodine chemistry.…”

“…The particular interest has been appealed by the N‐arylation of heterocycles. The electron‐rich heterocycles can be arylated by iodonium salts in relatively mild conditions, [37–40] while electron‐poor (especially cyclic amides and related compounds) require the addition of catalyst [41–46] . Also, the synthetic procedures for preparing diaryliodonium salts make available the versatile scope of these compounds with high yields from common laboratory reagents [47–54] …”

Copper-Catalyzed Selective Arylation of Oxadiazolones by Diaryliodonium Salts

“…[15][16][17] Modern approaches to the synthesis of diaryliodonium salts allow to prepare versatile scope of these compounds with high yields from common laboratory reagents. [18][19][20][21][22][23][24][25] Currently, diaryliodonium salts are widely used for arylation of N-nucleophiles, including amines, [26][27][28][29] amides, [30,31] and N-heterocycles [32][33][34][35][36][37][38] , etc. [39] Nevertheless, the chemoselectivity of arylation of N,O-containing heterocycles presents a challenging task in hypervalent iodine chemistry.…”