N-arylation of imides with arylboronic acids using Cu-Al hydrotalcite

N-Arylation of amines, amides, imides and sulfonamides with arylboroxines catalyzed by simple copper salt/EtOH system

“…Thus, a simple copper salt-catalyzed N-arylation of imides with arylboronic acids in protic solvent system had been developed in our previous reports [ 16 – 17 ]. Similar catalytic systems using non-halogenated hydrocarbon solvents have also been reported by Kantam and Prakash [ 18 – 19 ]. However, these procedures require an atmosphere of air or O 2 and the use of high temperature, even reflux conditions.…”

Copper-Promoted Carbon-Heteroatom Bond Cross-Coupling with Boronic Acids and Derivatives

“…16 Copper-aluminum hydrotalcite in refluxing methanol was also used in the N-arylation of imides with arylboronic acids with continuous air bubbling under base-free and solvent-free conditions. 17 One of the best examples to showcase the mild conditions of this chemistry is the copper-catalyzed N-arylation of labile azetidinone esters 15 by Devasthale's lab at Bristol-Myers Squibb. The N-arylated azetidinone esters 16 were obtained in nearly quantitative yields and, remarkably, with no racemization (Scheme 10).…”

Coupling of C-nitro-NH-azoles with arylboronic acids. A route to N-aryl-C-nitroazoles

“…The initial conditions of the reaction were based on those published by Lan et al [24] for coupling imidazole with phenylboronic acid. Most reports on the Chan–Lam coupling reaction underline the demand of air introduction into the reaction mixture to provide high yields of the products [22,24,36–37]. The plausible mechanism of this catalytic reaction was proposed by Evans [38] and described for N -nucleophiles by Collman [39].…”

“…Most known reports concerning N -arylation focus on Cu(OAc) 2 salt [21–22], complexes of Cu(II) with different ligands [23,36], and heterocyclic copper-based catalysts [25,37]. Basically, easily available simple copper(I) and copper(II) compounds, mostly salts, were investigated.…”