Three hyperbranched poly（siloxysilanes） were prepared from AB3-type monomers at the presence of Karstedt catalyst.The detailed synthesis procedures of AB3-type monomers by reaction between γ-methacryloyloxy propylt...Three hyperbranched poly（siloxysilanes） were prepared from AB3-type monomers at the presence of Karstedt catalyst.The detailed synthesis procedures of AB3-type monomers by reaction between γ-methacryloyloxy propyltrimethoxysilane or vinyltrimethoxysilane with chlorosilane using anhydrous ferric chloride as the catalyst were described.This new approach can simplify the synthetic routes for hyperbranched polysiloxanes.FTIR,（）1H-NMR,(（）13C-NMR,)（）29Si-NMR,elemental analysis and SEC/MALLS were employed to identify the structure of the polymers. The analyses revealed that the reaction between alkoxysilane and chlorosilane could be feasibly catalyzed by anhydrous ferric chloride.The reaction of vinyltrimethoxysilane with chlorosilane could be carried out more easily than that of γ-methylacrylacyloxypropyltrimethoxylsilane with chlorosilane due to its steric hindrance effect.展开更多
Synthesis of organosilanes from alkenes is a very important topic owing to their wide applications.A Ni/Cu dual metal-catalyzed arylsilylation of terminal alkenes,featuring migratory selectivity,has been developed.A w...Synthesis of organosilanes from alkenes is a very important topic owing to their wide applications.A Ni/Cu dual metal-catalyzed arylsilylation of terminal alkenes,featuring migratory selectivity,has been developed.A wide diversity of aliphatic silanes have been prepared from terminal alkenes,aryl halides and Suginome’s reagent.This protocol is highlighted by excellent regioselectivity,mild reaction conditions and good functional group tolerance.In addition to benzylic positions,carbon–carbon bonds can also be constructed at allylic positions.Preliminary mechanistic studies suggest that the copper cocatalyst promotes the transmetalation of Suginome’s reagent,and the addition of a Pyr Ox ligand inhibits the formation of side-products from the carbon-Heck pathway.Moreover,studies toward the nature of the Pyr Ox ligand revealed that the steric hindrance of the oxazoline moiety greatly affects the chain–walking process,but not the arylation step.展开更多
文摘Three hyperbranched poly（siloxysilanes） were prepared from AB3-type monomers at the presence of Karstedt catalyst.The detailed synthesis procedures of AB3-type monomers by reaction between γ-methacryloyloxy propyltrimethoxysilane or vinyltrimethoxysilane with chlorosilane using anhydrous ferric chloride as the catalyst were described.This new approach can simplify the synthetic routes for hyperbranched polysiloxanes.FTIR,（）1H-NMR,(（）13C-NMR,)（）29Si-NMR,elemental analysis and SEC/MALLS were employed to identify the structure of the polymers. The analyses revealed that the reaction between alkoxysilane and chlorosilane could be feasibly catalyzed by anhydrous ferric chloride.The reaction of vinyltrimethoxysilane with chlorosilane could be carried out more easily than that of γ-methylacrylacyloxypropyltrimethoxylsilane with chlorosilane due to its steric hindrance effect.
基金supported by the National Natural Science Foundation of China(21702151,21774029,and 21871211)the Fundamental Research Funds for Central Universities(2042019kf0208)。
文摘Synthesis of organosilanes from alkenes is a very important topic owing to their wide applications.A Ni/Cu dual metal-catalyzed arylsilylation of terminal alkenes,featuring migratory selectivity,has been developed.A wide diversity of aliphatic silanes have been prepared from terminal alkenes,aryl halides and Suginome’s reagent.This protocol is highlighted by excellent regioselectivity,mild reaction conditions and good functional group tolerance.In addition to benzylic positions,carbon–carbon bonds can also be constructed at allylic positions.Preliminary mechanistic studies suggest that the copper cocatalyst promotes the transmetalation of Suginome’s reagent,and the addition of a Pyr Ox ligand inhibits the formation of side-products from the carbon-Heck pathway.Moreover,studies toward the nature of the Pyr Ox ligand revealed that the steric hindrance of the oxazoline moiety greatly affects the chain–walking process,but not the arylation step.
