Copper-Catalyzed Regioselective Sila-Acylation and Silaformylation of 1,3-Dienes Using Esters

Synthesis of Cyclic Allylborates from 1,3-Dienes and a Diboron Reagent

The synthesis of cyclic allylborates was achieved by the reaction of 1,3-dienes and B₂ pin₂ using a copper catalyst. Several 1,3-dienes were converted to the corresponding cyclic allylborates in moderate to high yields. The cyclic allylborate obtained could be used in several organic transformations such as allylation of electrophiles and Suzuki-Miyaura coupling.

Copper-Catalyzed Regioselective Sila-acylation and Sila-imination of Allenes Using Esters and Nitriles

The sila-acylation of allenes is performed in the presence of a copper catalyst using PhMe2Si-B(pin) and esters as the silyl and acyl sources, respectively. β-Silyl-β,γ-unsaturated ketones are obtained regioselectively in good to high yields. The sila-imination of allenes is also achieved using nitriles as electrophiles. Exposure of the reaction mixture to air results in the production of cyclic silyl peroxides.