Efficient ligand-free copper-catalyzed N-arylation of amides with aryl halides in water

Copper catalysed Ullmann type chemistry: from mechanistic aspects to modern development

“…241 The use of PTCs such as TBAB or TPAB (tetraphenylammonium bromide) in aqueous coupling in the absence of ligands was also reported for thiophenols 242 and amides. 243 Apart from TBAB or similar PTCs, other compounds were reported to be effective in facilitating coupling reactions in water, such as PEG-400. 244 Interesting examples of multicomponent and domino reaction processes catalysed by Cu in water have also been reported.…”

Diversity-oriented synthesis of medium-sized cyclophanes via the photo-fries rearrangement of N-aryl lactams

“…Usually these kinds of compounds are obtained via a Cu(I)-catalyzed Goldberg-type C-N coupling reaction between aryl halides and lactams. [43][44][45][46][47][48][49][50] However, this procedure is only effective for N-arylation of 4-to 7-membered lactams, larger congeners remain unreactive no matter how we modified the catalytic systems (see ESI †). The Goldberg coupling is not, however, the only method of obtaining N-aryl lactams.…”

Copper Nanoparticles Supported on Zinc Oxide as Efficient Catalyst for the N‐Arylation of (Hetero)cyclic and Acyclic Amides

“…[8] An interesting ligandfree alternative using Cu 2 O as metal source, K 3 PO 4 as base and tetrabutylammonium chloride (TBAC) as phase-transfer catalyst in water, was presented by Teo et al, however the catalyst was not effective with aliphatic amides. [9] Copper nanoparticles, supported or unsupported, can be mentioned among the few heterogeneous catalytic systems reported in the literature for N-arylation of amides. In 2009, Punniyamurthi et al reported the use of unsupported CuO nanoparticles as catalyst for the N-arylation of amides, sulfonamides and oxazolidinones, in tBuOH-DMSO as solvent and different bases such as KOH, Cs 2 CO 3 and K 2 CO 3 .…”

“…In this field Buchwald [4] and Hartwig, [5] have made pivotal contributions, followed by Davies, [6] Taillefer, [7] and other authors [8] . An interesting ligand‐free alternative using Cu 2 O as metal source, K 3 PO 4 as base and tetrabutylammonium chloride (TBAC) as phase‐transfer catalyst in water, was presented by Teo et al., however the catalyst was not effective with aliphatic amides [9] …”