Probing the Impact of Added Al(OTf)₃ on DalPhos/Nickel‐Catalyzed N‐Arylations of Amides with (Hetero)aryl Chlorides

Abstract

We disclose herein our study examining the potential activating effect of added aluminum triflate (5 mol%) on the (DalPhos)Ni(aryl)Cl (1 mol% Ni) catalyzed C‐N cross‐coupling of primary amides with (hetero)aryl chlorides. In some instances, dramatically improved conversion to product was achieved by use of added aluminum triflate; with furfurylamine catalytic inhibition occurred. The reaction outcome appears to result from the interplay of DalPhos ligand and aryl group within the Ni pre‐catalyst, as well as the identity of the cross‐coupling partners.

The development of cage phosphine ‘DalPhos’ ligands to enable nickel-catalyzed cross-couplings of (hetero)aryl electrophiles

“…Given that catalytic turnover may require loss of L 0 , in a followup report in 2023 we probed whether the addition of a Lewis acid may facilitate L 0 loss and regeneration of putative '(PAd2-DalPhos)Ni'. 66 In this study we established that the addition of AlOTf 3 (5 mol%) to amide C-N cross-coupling reactions employing (PAd2-DalPhos)Ni(4-CN-Ph)Cl (1 mol%) can in some instances greatly facilitate catalytic turnover.…”