Copper-Mediated Transformation of Organosilanes to Nitriles with DMF and Ammonium Iodide
作者:Zhen Wang、Sukbok Chang
DOI:10.1021/ol400659p
日期:2013.4.19
Cyanation of aryl-, diaryldimethyl-, and styrylsilanes was developed for the first time under copper-mediated oxidative conditions using ammonium iodide and DMF as the combined source of nitrogen and carbon atom of the introduced cyano unit, respectively. The reaction was observed to proceed in a two-step process: initial conversion of organosilanes to their iodo intermediates and then cyanation. This method has a broad substrate scope with high functional group tolerance.
Further studies of fluoride ion entrapment in octasilsesquioxane cages; X-ray crystal structure studies and factors that affect their formation
作者:Peter G. Taylor、Alan R. Bassindale、Youssef El Aziz、Manuel Pourny、Richard Stevenson、Michael B. Hursthouse、Simon J. Coles
DOI:10.1039/c1dt11340b
日期:——
A range of fluoride-encapsulated octasilsesquioxane cage compounds have been prepared using the TBAF route. Our studies suggest that whilst it is relatively straightforward to prepare fluoride-encapsulated octasilsesquioxane cage compounds with adjacent sp2 carbons, leading to a range of aryl and vinyl substituted compounds, the corresponding sp3 carbon derivatives are more capricious, requiring an electron withdrawing group that can stabilize the cage whilst not acting as a leaving group. Analysis by X-ray crystallography and solution 19F/29Si NMR spectroscopy of R8T8@F− reveal very similar environments for the encapsulated fluoride octasilsesquioxane cages. Migration of a fluoride ion from inside the cage to outside the cage without breaking the T8 framework and the possibility of encapsulating other anions within silsesquioxane cages have been also investigated.
Distinct Catalytic Performance of Dirhodium(II) Complexes with <i>ortho</i>-Metalated DPPP in Dehydrosilylation of Styrene Derivatives with Alkoxysilanes
provided a stable and rigid dirhodium(II) complex with ortho-metalated DPPP as the bridging ligand and the phosphonate as the axial ligand in the catalytic system. The structure of the dirhodium(II) complexes was also supported by X-raycrystal diffraction. Further experiments confirmed that the dirhodium(II) complexes may be the active species that catalyze the dehydrosilylation reaction. Control experiments