Chan−Lam Arylation of Benzimidazole and its Derivatives in the Presence of Copper‐Containing Minerals

Abstract

Copper catalysis plays a remarkable role in synthetic organic chemistry. The catalytic activity of copper-containing minerals is not sufficiently presented in the literature, even though the economical value of such procedures is rather high. With the direct usage of these readily available ores, the highly polluting industrial copper production can be avoided. In the present work, the copper-containing mineral catalyzed ChanÀ Lam reaction of benzimidazole, substituted benzimidazoles or imidazole with various phenylboronic acids is described. A total of nine readily available ores were tested in our model reaction with bornite (Cu 5 FeS 4) and chalcocite (Cu 2 S) being the best among them. The in situ formed catalytic system of Cu 5 FeS 4 / TMEDA was able to produce the desired products in up to 98 % yields and it was reusable making this process even more economical and environmentally friendly.

Copper‐Containing Mineral Mediated Glaser Coupling of Terminal Alkynes

“…In our previous research using a similar system for the Chan-Lam arylation of benzimidazole compounds, the catalytic system proved to be reusable. [30] Therefore, similarly to our previous experiments, after carrying out the reaction, the mixture was filtrated using a G4 glass filter and the obtained residue was reused in two more cycles for both pyrrolidineand TMEDA-based systems (Figure 2).…”

“…[29] Furthermore, the arylation of benzimidazole and its derivatives under Chan-Lam conditions can be catalyzed by sulfide-type copper minerals such as chalcocite (Cu 2 S) and bornite (Cu 5 FeS 4 ). [30] Apart from these examples, Bolm showcased the catalytic applicability of covellite (CuS) in the preparation of six five-membered cyclic amides in Kharasch reaction. [31] In this study, we wish to present the copper mineralassisted Glaser coupling reaction of terminal alkynes.…”

“…The catalytic activity of such minerals was, to the best of our knowledge, first observed in our laboratory, when we have shown that the multicomponent reaction of an aldehyde, an amine and an alkyne (A 3 reaction) could be efficiently catalyzed by azurite [Cu 3 (CO 3 ) 2 (OH) 2 ], chrysocolla [(Cu,Al) 2 H 2 Si 2 O 5 (OH) 4 ⋅n H 2 O], brochantite [Cu 4 (SO 4 )(OH) 6 ] and malachite [Cu 2 (CO 3 )(OH) 2 ] [29] . Furthermore, the arylation of benzimidazole and its derivatives under Chan–Lam conditions can be catalyzed by sulfide‐type copper minerals such as chalcocite (Cu 2 S) and bornite (Cu 5 FeS 4 ) [30] . Apart from these examples, Bolm showcased the catalytic applicability of covellite (CuS) in the preparation of six five‐membered cyclic amides in Kharasch reaction [31] …”

Green synthesis of shape-tunable CuFe2O4NPs: a magnetically retrievable and efficient catalyst for Chan–Lam type C–N coupling reactions under base-free conditions

“…9,10 Hence to improve the yield and efficacy of the Chan-Lam reaction, as well as to overhaul the downsides, various modifications have been made over the years using Cu, copper-based salts and ligands. [11][12][13][14][15] Despite the paramount role of Cu-based homogeneous catalysts, their recovery for successive uses has become an issue for industrial applications. 16 To combat the recovery, and hence the reusability issues, heterogeneous catalysts are extensively used under various reaction conditions for C-N coupling reactions.…”

N,N′-Dimethylurea as an efficient ligand for the synthesis of pharma-relevant motifs through Chan–Lam cross-coupling strategy

“…Later developments have significantly contributed to overcoming these drawbacks, making Chan-Lam cross-coupling a preferred C-N bond-forming approach over existing protocols. [35][36][37][38][39][40][41][42] Chan-Lam cross-couplings are also strategies of choice for the formation of target bonds in multi-step reactions; designed for the synthesis of significant heterocyclic scaffolds. Some of these reactions are assisted by visible light as well.…”