A higher yielding route to octasilsesquioxane cages using tetrabutylammonium fluoride, Part 2: further synthetic advances, mechanistic investigations and X-ray crystal structure studies into the factors that determine cage geometry in the solid state
作者:Alan R. Bassindale、Huiping Chen、Zhihua Liu、Iain A. MacKinnon、David J. Parker、Peter G. Taylor、Yuxing Yang、Mark E. Light、Peter N. Horton、Michael B. Hursthouse
DOI:10.1016/j.jorganchem.2004.06.063
日期:2004.10
of scarce water provides a higher yielding route to substituted octasilsesquioxane cages. Further cages have now been prepared in good yield using this route and their X-ray crystalstructures demonstrate that their cage geometries in the solid state are very similar with the packing constraints of the crystal lattices appearing to have the greatest influence on the geometry of the cage core. The mechanism
Metal-catalyzed alkylation of 1,1-dihalovinyl moiety commonly suffers from both a lack of stereoselectivity and the overreaction leading to the dialkylation product. The methodology described herein features a new pathway to alkylate stereoselectively β,β-dichlorostyryl substrates to provide the Z-trisubstituted olefin only with fair to good yields. This cross-coupling reaction bears on the smooth
The present invention relates to a method for preparing di-organo-dialkoxysilanes, in particular di-organo-dialkoxysilanes wherein one or both of the organic substituents are bulky. The method comprises reacting a tetraalkoxysilane compound with a first Grignard reagent to form a mono-organo-tri-alkoxysilane compound, which is then reacted with a chlorinating agent to form a chlorinated mono-organo-di-alkoxysilane which is then reacted with a second Grignard reagent to form the di-organo-di-alkoxysilane compound.
Stereoselective Palladium-Catalyzed Hiyama Cross-Coupling Reaction of Tetrasubstituted <i>gem</i>-Difluoroalkenes
作者:Min Li、Gavin Chit Tsui
DOI:10.1021/acs.orglett.3c04037
日期:2024.1.12
We herein describe a diastereoselective Pd(0)-catalyzed Hiyama cross-coupling reaction of gem-difluoroalkenes. The use of organosiliconreagents in this reaction is advantageous over other organometallic reagents by allowing the introduction of a wide range of functional groups, including challenging alkyl groups. Also conveniently, the additive TBAF was not required for (hetero)aryl-substituted difluoroalkenes