N-Arylation of Amines with o-Silylaryl Triflate

Abstract

An efficient, transition-metal-free procedure for the N-arylation of amines 1 has been achieved by allowing those substrates to react with o-silylaryl triflate 2 in the presence of CsF. Good to excellent yields of arylated products 3 are obtained under very mild reaction conditions. This chemistry readily tolerates a variety of functional groups.

o-Silylaryl Triflates: A Journey of Kobayashi Aryne Precursors

“…Subsequently, Larock et al systematically investigated the arylation reactions of o -silylaryl triflates with amines (R 2 = aryl, alkyl), sulfonamides (R 2 = R′SO 2 ), carbamates (R 2 = CO 2 Et), and benzamides (R 2 = ArCO) (Scheme a). , Depending on the stoichiometry of aryne precursors, either monoarylated products 5-3 or diarylated products 5-4 could be obtained in moderate to excellent yields. Moreover, Jung and co-workers found that the N-arylation reaction of aromatic amines with benzyne proceeded smoothly in the presence of either 2,5-dimethoxytetrahydrofuran or 1,3-diacetone dicarboxylic acid . Different from the copper-mediated Ullmann reaction and the palladium-catalyzed Buchwald–Hartwig C–N coupling reaction, this method is under transition-metal-free conditions.…”

“…Moreover, Jung and co-workers found that the N-arylation reaction of aromatic amines with benzyne proceeded smoothly in the presence of either 2,5dimethoxytetrahydrofuran or 1,3-diacetone dicarboxylic acid. 361 Different from the copper-mediated Ullmann reaction and the palladium-catalyzed Buchwald−Hartwig C−N coupling reaction, this method is under transition-metal-free conditions. Unsubstituted primary or N-alkyl amides, however, were inert under arylation conditions, which was reasoned by their weak nucleophilicity.…”

Photochemical synthesis of π-extended ullazine derivatives as new electron donors for efficient conjugated D–A polymers

“…21 Then, the formation of the pyrrole was achieved using the Clauson-Kass reaction between compound 1 and 2,5dimethoxytetrahydrofuran in the mixture of AcOH and 1,2dichloroethane. 22 A two-fold borylation reaction using copper iodide (CuI) as the catalyst 23 gave compound 3 that was coupled to 2-bromo-3-chloropyridine and 3-bromo-2-chloropyridine using Pd(dppf)Cl2 as the catalyst to give compounds 4 (81%) and 6 (88%), respectively. Likewise, coupling with 2-bromo-3chlorothiophene and 3-bromo-2-chlorothiophene using PdCl2(PPh3)2 as the catalyst give compounds 8 (89%) and 10 (86%), respectively.…”