A New, Efficient and Recyclable Lanthanum(III) Oxide‐ Catalyzed CN Cross‐Coupling

Abstract

A new and efficient protocol for the C À N cross-coupling of aryl halides with heteroaromatic amines in the presence of lanthanumA C H T U N G T R E N N U N G (III) oxide (10 mol%) as a recyclable catalyst, N,N'-dimethylethylenediamine (DMEDA) (20 mol%) and potassium hydroxide (KOH) as a base in dimethyl sulfoxide (DMSO) at 110 8C has been developed. This inexpensive catalytic system is highly effective towards the amination of aryl halides with various nitrogen nucleophiles and is significantly tolerant towards other functional groups in the substrates.

C–N bond forming cross-coupling reactions: an overview

“…Recently, a new and efficient method for C-N bond formation through cross-coupling reaction of aryl halides (iodide or bromide) 95 with aromatic/heteroaromatic amines 96 has been reported by Nageswar and co-workers, 38 employing lanthanum(III) oxide (10 mol%), DMEDA (20 mol%) and KOH as base in DMSO. The resulting N-arylated derivatives 97 have been isolated in high yields (Scheme 27).…”

Silver‐Nitrate‐Catalyzed N‐Arylation of Amines and O‐Arylations of Phenols and Alcohols

“…By lowering the temperature, the reaction took a longer time and the yield was also not satisfactory. The effect of ligands and the silver(I) salts were verified by carrying out several reactions with various ligands ( Table 2, entries 1-11) and silver(I) salts ( Table 2, entries [12][13][14][15][16]. N,N-DMEDA, N,N'-DMEDA, and tetramethylethylenediamine (TMEDA) were effective and N,N-DMEDA gave the highest yield in 8 h. Besides these, other ligands provided 40-60 % yields of the coupled product.…”

“…N,N-DMEDA, N,N'-DMEDA, and tetramethylethylenediamine (TMEDA) were effective and N,N-DMEDA gave the highest yield in 8 h. Besides these, other ligands provided 40-60 % yields of the coupled product. A number of silver(I) salts were tested ( Table 2, entries [12][13][14][15][16] and AgNO 3 gave the best results. Moreover, without any ligand (Table 2, entry 9) and without a silver(I) source ( Table 2, entry 17), only 10 % and 5 % yields of product were isolated, respectively.…”

“…These compounds are the precursors or subunits in various compounds related to biological, pharmaceutical, and medicinal chemistry. [13] In the last few decades, numerous methods have been developed for synthesizing N-arylated and O-arylated motifs. As copper salts are inexpensive relative to palladium, they received intense attention in research involving coupling reactions [14][15][16][17][18] and copper was first introduced into coupling chemistry in the early nineteenth century by Ullmann and Bielecki.…”

“…[20] Methods developed by the groups of Liu, [21] Bolm, [22] and Taillefer [23] have also received considerable attention. Besides these, other metals, such as nickel, [24] cobalt, [25] cadmium, [26] and lanthanum, [13] have been reported for N-arylation and O-arylation.…”