A ligand-free copper(I) oxide catalyzed strategy for the N-arylation of azoles in water

Recent Progress Concerning the N-Arylation of Indoles

“…In addition, indole N -arylations have been the subjects of ligandless experimental setups. This approach for the preparation of N -aryl azoles, including N -arylindoles, was reported by Teo in 2011 ( Scheme 21 ) [ 91 ]. The reaction of unsubstituted indoles with aryl iodides in the presence of catalytic amounts of copper oxide and tetrabutylammonium bromide (TBAB) as phase-transfer catalysts in water gave N -arylindoles S21-2 in high isolated yields.…”

Base-Promoted SNAr Reactions of Fluoro- and Chloroarenes as a Route to N-Aryl Indoles and Carbazoles

“…N-(2-Chlorophenyl)indole ( 3ba ) [49]: White waxy oil (111.5 mg, 49%); 1 H-NMR (400 MHz, CDCl 3 ) δ 7.70 (d, J = 6.5 Hz, 1H), 7.61–7.58 (m, 1H), 7.47–7.39 (m, 3H), 7.26–7.13 (m, 4H), 6.71 (d, J = 3.3 Hz, 1H); 13 C-NMR (100 MHz, CDCl 3 ) δ 137.0, 136.8, 131.9, 130.9, 129.5, 129.1, 128.8, 128.6, 127.7, 122.4, 121.1, 120.4, 110.7, 103.3; GC-MS m / z : 227 (M + ).…”

Direct Catalytic Functionalization of Indazole Derivatives

“…of K 3 PO 4 as a base in water at 130°C for 24 h producing desired N-1 arylated 1Hindazole products (12 b) up to 83% yields (Scheme 12). [78] Two years later, the same group again reported ligand-free N-1 heteroarylation of 1H-indazole (13 a) using Cu 2 O as a catalyst, Cs 2 CO 3 as a base in DMSO at 100°C for 24 h. The desired N-1 heteroarylated 1Hindazole product (13 b) was formed with 90% yield (Scheme 13). [79] Guillaumet's group reported an efficient and facile method for direct C-3 arylation of 1H-indazoles (14 a) using aryl iodide or bromide as a coupling partner, Pd (OAc) 2 as a catalyst, 1,10-phenanthroline as a ligand, K 2 CO 3 as base and DMA as the solvent.…”