A Highly Versatile Catalytic System forN‐Arylation of Amines with Aryl Chlorides in Water

Abstract

The C–N coupling between nucleophiles and aryl chlorides, which are less expensive, less reactive, and more abundant than their bromide and iodide counterparts, is challenging but of great interest for industrial applications. An oxalyldihydrazide/hexane‐2,5‐dione (100–150 mol‐%)/CuO system was found to enable the reaction of a wide range of nucleophiles with a variety of aryl chlorides in water for the first time.

Amination of Aryl Halides by Using an Environmentally Benign, Recyclable Copper Catalyst

“…In 2010, Zhou and co‐workers8 reported a sulfonato–Cu(salen) complex catalyst for the reaction of a wide range of aryl bromides and iodides with aqueous NH 3 to afford good to excellent yields at 120 °C within 12 h with KOH as the base. Also at that time, we realized the CuO/ N 2 , N 2 ′ ‐diisopropyloxalohydrazide‐catalyzed direct amination of aryl bromides and iodides with aqueous NH 3 at 60 °C;9 shortly thereafter, in 2011, the previously reported three‐component catalyst CuO/oxalyldihydrazide/hexane‐2,5‐dione was identified to be effective for the direct amination of aryl chlorides with aqueous NH 3 10…”

Ethylene glycol, an efficient and recoverable medium for copper-catalyzedN-arylation of diazoles under microwave irradiation

“…13 The NMR data are in good agreement with those reported. [3] 1-(3-methoxyphenyl)-1H-imidazole (1d): Colorless oil. [5] 1 H NMR (CDCl 3 , 500 MHz) δ (ppm) 7.84 (s, 1H); 7.35 (t, J = 8.0 Hz, 1H); 7.26 (s, 1H); 7.18 (s, 1H); 6.95 (m 1H); 6.87 (m, 2H); 3.83 (s, 3H).…”

“…The NMR data are in good agreement with those reported. [3] 1-p-tolyl-1H-pyrazole (1i): m.p: 28-30 °C (literature, 28-30°C). [1] 3.…”

Functionalised Chitosan as a Green, Recyclable, Supported Catalyst for the Copper-Catalysed Ullmann C-N Coupling Reaction in Water

“…[4,5] More recently, increasingly many copper-catalysed C-N bond-forming reactions were performed in aqueous media or pure water. [6][7][8][9][10][11][12][13] However, because the catalyst and ligand usually remain in water, the greenness of water used as a solvent has been repeatedly questioned. Compared to homogeneous catalysts, the advantages of a heterogeneous catalysis are ease of product separation, recovery and recyclability.…”