Palladium-Catalyzed Coupling of Ammonia and Lithium Amide with Aryl Halides

Abstract

A mild, palladium-catalyzed coupling of aryl halides with ammonia or lithium amide to form primary arylamines as the major product is described. These reactions occurred with excellent selectivity for formation of the primary arylamine over formation of the diarylamine (9.5:1 to over 50:1 ratios of arylamine to diarylamine). In addition, the first organopalladium complex with a terminal -NH2 ligand has been isolated. This complex reductively eliminates to form arylamines.

Avanços recentes na hidroaminação de compostos insaturados

“…Trabalhos de Hartwig 14 e Buchwald 15 sobre acoplamento de haletos de arila com amônia, via catálise de paládio, abriram caminho para estudos do seu uso em reações de hidroaminação.…”

“…Essa metodologia foi utilizada com sucesso para a preparação de diversos N-heterociclos substituídos: pirrolidinas (96-98), octaidroindol (99), piperidinas (100-101), morfolina (102) 14, tornando a ciclização exo favorecida em relação à ciclização endo. Nos casos em que mais de um centro estereogênico foi criado (99 e 101), baixa diastereosseletividade foi observada.…”

Direct Synthesis of Secondary Amines From Alcohols and Ammonia Catalyzed by a Ruthenium Pincer Complex

“…Because of the abundance and low price of ammonia, much attention has been focused on its use as a nitrogen source for organic synthesis [4,5]. Recent reports on homogenous catalytic systems using ammonia as the substrate include palladium-catalyzed telomerization of butadiene and ammonia giving primary alkylamines [6], Pd-catalyzed allylic amination [7], copper-and palladiumcatalyzed coupling reactions of ammonia with aryl halides to form arylamines [8][9][10], rhodium-and iridium-catalyzed reductive aminations of carbonyl compounds with ammonium formate and ammonia to afford primary alkylamines [11][12][13] and palladium-catalyzed arylation of ammonia to afford di-and triarylamines [10].…”

An Efficient Copper‐Catalyzed Amination of Aryl Halides by Aqueous Ammonia

“…[2] In recent years, transition metalmediated reactions such as palladium-or copper-catalyzed couplings of aryl halides with ammonia or ammonia surrogates to afford the desired anilines under mild conditions have been reported. [3,4] More recently, Fu et al [5] reported a ligand-free copper-catalyzed arylation of aqueous ammonia with aromatic boronic acids at room temperature. However, the Pd-catalyzed synthesis of anilines from ammonia or ammonia surrogates usually requires the use of strong bases, toxic phosphorus ligands and rare metallic catalysts.…”

“…The catalytic efficiency of the other ligands was also evaluated in the same reaction system. [1][2][3][4][5]6,7,)-2-methylpropan-1-one (L3), a close analogue of L2, displayed the best catalytic activity ( Table 1, entry 4). Thus, L3 was chosen as the ligand for the following optimization of the reaction conditions.…”