Synthesis of Hindered Anilines: Copper‐Catalyzed Electrophilic Amination of Aryl Boronic Esters

Abstract

No longer a hindrance: copper-catalyzed electrophilic amination of aryl boronic esters is accomplished under mild reaction conditions using 2.5-5.0 mol % of a catalyst derived from copper tert-butoxide and Xantphos ligand. The reaction tolerates a wide range of functional groups and can be used to prepare some of the most hindered anilines made to date.

Elusive Metal-Free Primary Amination of Arylboronic Acids: Synthetic Studies and Mechanism by Density Functional Theory

“…Moreover, certain functional groups are incompatible with transition metals; for example, the preparation of mono- and polyhalogenated anilines 6e is often not possible under transition metal catalysis due to competing cross-coupling processes.…”

Copper-Catalyzed Electrophilic Amination of Organolithiums Mediated by Recoverable Siloxane Transfer Agents

“…2 An umpolung tactic, involving transition metal-catalyzed amination of organometallic reagents with electrophilic aminating reagents (e.g., chloroamines and hydroxylamines), provides a valuable complementary approach. 3 Indeed, various organometallic reagents are known to undergo electrophilic amination, including organomagnesiums, 4 organozincs, 5 organotins, 6 organoborons, 6,7 organosilicons, 8 and organotitaniums. 9 These reagents however are frequently prepared from the corresponding organolithium reagents.…”

Two cadmium(II) complexes with oxazoline-based ligands as effective catalysts for C–N cross-coupling reactions

“…The binuclear (2) 2.8231 (5) 3.7744 (23) 167.08(12) C(12)-H(12A)Á Á ÁCl (2) 2.8150 (5) 3.6899 (25) 150.39 (15) complexes 1 and mononuclear 2 were characterized by IR and elemental analysis. Both compounds are stable towards air and moisture in the solid state.…”

“…The palladium-catalyzed cross-coupling of aryl amine with aryl halide and pseudo halide is most popular method in this transformation [18,19]. Besides palladium, other catalytic systems using manganese [20], iron [21], cobalt [22], nickel [23,24], copper [25,26], indium [27], gold [28] and rhodium [29] have also been reported for the same purpose. However, among these transition metal complexes, cadmium complexes with oxazoline-based ligands have not received much attention [30].…”