RESUMEN
A transition-metal-free method for the alkylation of gem-diborylalkanes with α,ß-unsaturated ketones has been developed. It is demonstrated that the α-boryl radicals can be generated efficiently from gem-diborylalkanes with the aid of catechol and oxidants. The α-boryl radicals formed through such process can be engaged in conjugate addition reaction with α,ß-unsaturated ketones. This transformation is a straightforward method for the synthesis of γ-borylketones.
RESUMEN
A transition-metal-free method for the synthesis of gem-silylboronate esters with arylboronic acids and trimethylsilyldiazomethane (TMSCHN2) has been developed. This transformation is a straightforward homologation of arylboronic acids and features wide substrate scope and good functional-group tolerance. The gem-silylboronate esters undergo efficient Suzuki-Miyaura cross-coupling with aryliodides and the silyl group of the product can be further functionalized. Tertiary carbon centers with different substituents can be constructed successfully by selective and sequential functionalization.
RESUMEN
A palladium-catalyzed cross-coupling reaction of electron-deficient aryl fluorides with aryl N-tosylhydrazones has been reported. Mechanistically, this approach involves C-F bond activation and migratory insertion of palladium carbene as the two key steps.
RESUMEN
Transition-metal-free synthesis of α-aryl esters and nitriles using arylboronic acids with α-aminoesters and α-aminoacetonitriles, respectively, as the starting materials has been developed. The reaction represents a rare case of converting C(sp(3))-N bonds into C(sp(3))-C(sp(2)) bonds. The reaction conditions are mild, demonstrate good functional-group tolerance, and can be scaled up.
