Mild‐Base‐Promoted Arylation of (Hetero)Arenes with Anilines

Abstract

Transition metal-free radical arylation of heteroarenes is achieved at room temperature by simply adding aqueous sodium carbonate to a solution of the corresponding heteroarene and arenediazonium salt, which can even be formed in situ. Such an easy, inexpensive and mild methodology has been optimized and applied to the expeditious modification of interesting molecular cores like naphthylimide or bisthienylcyclopentenes.

Recent Advances in the Transition-Metal-Free Arylation of Hetero­arenes

“…Radical arylation of furans, thiophenes, and N-Boc pyrroles with anilines or arenediazonium salts was reported by Carrillo and co-workers in 2018 (Scheme 15). 24 When the arenediazonium salts were the source of aryl, the reaction was carried out in the presence of sodium bicarbonate solution.…”

“…Radical arylation of furans, thiophenes, and N-Boc-pyrroles with anilines or arenediazonium salts was reported by Carrillo and co-workers in 2018 (Scheme 15). 24 When an arenediazonium salt was the source of the aryl group, the reaction was carried out in the presence of Na 2 CO 3 solution (Method A). When the arylation reagent was an arylamine then methanesulfonic acid was used together with t-BuONO (Method B).…”

Single‐Electron‐Transfer‐Initiated Sequential Direct Arylation Reaction of Pyrrole with Aryl Diazonium Salts

“…[19] Moreover, Carrillo demonstrated that the mild base promoted arylation reaction using aniline as an arylation reagent. [20] Although these developed reaction are excellent method to use aryl radical from stable aniline derivatives, complicated operation are required.…”

Synthesis of 2-Arylpyridines and 2-Arylbipyridines via Photoredox-Induced Meerwein Arylation with in Situ Diazotization of Anilines

“…Methoxyphenyl)-4,6-dimethylpyridine (7): Following the general procedure using 2,4lutidine (277 μL, 2.4 mmol) and 4-methoxyaniline (74 mg, 0.6 mmol), the residue was purified by flash chromatography on silica gel (heptane-EtOAc, 95-5) to afford the desired compound 7 (73 mg, 56%) as a yellow solid. 1 H NMR (300 MHz, CDCl 3 ) δ 7.94 (d, J = 8.6 Hz, 1H), 7.30 A c c e p t e d m a n u s c r i p t(s, 1H), 6.99 (d, J = 8.6 Hz, 1H), 6.90 (s, 1H), 3.87 (s, 3H), 2.58 (s, 3H), 2.37 (s, 3H) 13. C{ 1 H} NMR (75 MHz, CDCl 3 ) δ 160.1, 157.9, 156.5, 147.6, 132.5, 128.2, 121.9, 117.9, 113.9, 55.3, 24.5, 21.0.…”

“…Following the general procedure using 2-bromopyridine (229 μL, 2.4 mmol) and 4chloroaniline (76 mg, 0.6 mmol), the residue was purified by flash chromatography on silica gel (heptane-EtOAc, 70-30) to afford the desired compounds11a (58 mg, 36%) as a white solid and 11b (51 mg, 32%) as a white solid. 11a 1 H NMR (400 MHz, CDCl 3 ) δ 7.96 (d, J = 8.5 Hz, 2H), 7.68 (d, J = 7.6 Hz, 1H), 7.62 (t, J = 7.7 Hz, 1H), 7.48 -7.42 (m, 3H) 13. C NMR (400 MHz, CDCl 3 ) δ 157.3, 142.2, 139.1, 136.0, 135.9, 129.0, 128.2, 126.6, 118.8.…”