Cu(I) mediated hydrogen borrowing strategy for the α-alkylation of aryl ketones with aryl alcohols

New triazolium Schiff bases (TSBs) were synthesised via a simple and high throughput process. The new salts were successfully characterised. When reacted with Cu(CH 3 CN) 4 PF 6 , the TSB salts formed mononuclear triazole Schiff base copper(I) complexes and dinuclear complexes that were also characterised. The copper complexes were generated in situ (mixtures of TSB salts with Cu(CH 3 CN) 4 PF 6 ) and applied as homogeneous catalysts for the C–C coupling of a variety of aryl ketones with aryl alcohols, from which significant reactivity was observed. Reaction conditions were optimised, and the results indicate that the catalyst systems are very robust. A catalyst concentration of 10 mol% efficiently and selectively catalysed the α -alkylation of methyl phenyl ketone and its derivatives to afford up to 94% yield of 1,3-diphenylpropan-1-one and its analogues. The process is adaptable with analogues of acetophenone and benzyl alcohol bearing various regulating substituents tolerated. Graphic abstract