Ligandless Regioselective Hydrosilylation of Allenes Catalyzed by Gold Nanoparticles
摘要:
The first example of Au-catalyzed hydrosilylation of allenes is presented using recyclable gold nanoparticles as catalyst, without the requirement of any external ligands or additives. The hydrosilane addition takes place on the more substituted double bond of terminal allenes in a highly regioselective manner. The observed regioselectivity/reactivity modes are attributed to steric and electronic factors.
Cu(I)-NHC-Catalyzed Silylation of Allenes: Diastereoselective Three-Component Coupling with Aldehydes
作者:James Rae、Ya Chu Hu、David J. Procter
DOI:10.1002/chem.201404330
日期:2014.10.6
Copper‐catalyzed silylation of aryl allenes using a silylborane reagent affords vinyl silane building blocks with high efficiency. The use of a seven‐membered NHC ligand proved crucial for high regioselectivity. The catalytically generated allylcoppper intermediates were intercepted by aldehydes in a diastereoselective three‐component coupling to furnish homoallylic alcohols.
new approach for regio‐controlled synthesis of exo/endo‐vinylsilanes through silylzincation as a key reaction, using newly developed silylzinc reagents. In this system, by choosing appropriate zinc reagents, either exo‐vinylsilane or endo‐vinylsilane can be synthesized with good regioselectivity, using the same phenylallene substrates.