Carbothioamide as Highly Efficient Ligand for Copper‐catalyzed Room Temperature Chan–Lam Cross‐Coupling Reaction

Abstract

The catalytic activity of three N,S‐donor ligands, viz L1 [2‐(4‐methoxybenzylidene)‐N‐phenylhydrazinecarbothioamide], L2 [2,2′‐(1,2‐diphenylethane‐1,2‐diylidene)bis(hydrazinecarbothioamide)] and L3 [2‐(4‐methoxybenzylidene)hydrazinecarbothioamide] has been reported for N‐arylation of imidazoles with arylboronic acids in ethanol at room temperature. The method was found to be applicable in N‐arylation for a wide range of electronically diverse arylboronic acids with imidazoles having modest to excellent isolated yields. The in situ generated copper(II) complex of the ligand namely, 2‐(4‐methoxybenzylidene)‐N‐phenylhydrazinecarbothioamide (L1) was found to be highly efficient homogeneous catalyst for N‐arylation reaction.

Graphene Oxide Immobilized Copper(II) Schiff Base Complex [GO@AF‐SB‐Cu]: A Versatile Catalyst for Chan‐Lam Coupling Reaction

“…Our interest lies in the design and development of novel heterogeneous catalysts for Chan‐Lam coupling reaction. The Chan‐Lam coupling reaction has been studied in depth with various homogeneous and heterogeneous catalysts such as Cu(OAc) 2 /[2‐(4‐methoxybenzylidene)‐ N ‐phenylhydrazine‐carbothioamide], N, O‐bidentate‐chelated ligand‐tunable Cu(II) complex, NiCl 2 .6H 2 O/2,2’‐bipyridyl, Ni(OAc) 2 .4H 2 O/ N ‐(pyridine‐2‐yl)benzamide, CuFAP, polymer supported Cu(II) complex, Fe 3 O 4 ‐EDTA−Cu(II) complex, Wang resin supported Cu(II) catalyst, (MPI−Cu), silica based Ni(II) nanocatalyst, fac‐[Ir(ppy) 3 ]‐assisted Cu(II) catalyst, Cu/MCIP‐1 and chitosan anchored Cu(II) catalyst etc. Many of the reported methods still suffer from several demerits such as recyclability of catalyst, prolong reaction time, use of toxic solvents and high temperature etc.…”

Iron oxide encapsulated by copper-apatite: an efficient magnetic nanocatalyst for N-arylation of imidazole with boronic acid

“…At the turn of the 21 st century, recent development of Narylation with boronic acids unleashed the power of Cheteroatom bond formation reaction due to the mild reaction conditions (room temperature, weak base and ambient atmosphere). [10][11][12][13] However, the synthetic scope of this reaction is strongly limited due to some disadvantages, such as product contaminationtoxic waste produced aer separation of the catalyst, which cannot be easily recovered aer the reaction. 14 These disadvantages can be overcome by anchoring the metal on suitable supports, which can be easily recovered, and then potentially be reusable with a minimal amount of product contamination.…”