Acyl Fluorides as Efficient Electrophiles for the Copper-Catalyzed Boroacylation of Allenes

The copper-catalyzed reaction of allenes with bis­(pinacolato)­diboron and acyl electrophiles is reported. In this transformation, acyl fluorides have been proven to be more efficient coupling partners than their chloride or carboxylate analogues. The optimized reaction conditions employed were shown to be compatible with a range of commonly used functional groups, thereby allowing the formation of a library of β-boryl β,γ-unsaturated ketones by varying the nature of the allene and acyl fluoride substrates.