Suzuki-Miyaura Cross-Coupling of Trifluoroboratohomoenolates

organotrifluoro-borates - cross-coupling - homoenolates

Significance

The application of the corresponding alkyltrifluoroborates as nucleophiles in a cross-coupling reaction with aryl and alkenyl halides or triflates allowed a simple preparation of various 2-arylethyl ketones, amides and esters. The method tolerates a broad variety of functional groups, and, due to its simplicity and excellent versatility, can be very useful in combinatorial synthesis and creation of compound libraries.

Comment

The trifluoroboratoenolates were prepared via the Cu(I)-catalyzed conjugate addition of bis(pinacolato)diboron to unsaturated carbonyl compounds (S. Mun, J.-E. Lee, J. Yun Org. Lett. 2006, 8, 4887), followed by the treatment with KHF₂. Another variant is the C-alkylation of enolates with iodomethylpinacol boronate (A. Whiting Tetrahedron Lett. 1991, 32, 1503). Most alkyltri­fluoroborates are known to be very convenient to handle, stable free-flowing powders.