Transition-Metal Catalyzed Hydrosilylation Of Unsaturated C-C Bonds

Organosilanes are widely used in organic synthesis.Transition metal-catalyzed hydrosilylation of C-C unsaturated bonds has emerged as one of the most useful methods for the synthesis of organosilanes.Transition metal-catalyzed hydrosilylation reaction has been well developed in the past several decades.Early studies focused on the use of precious metals such as platinum,rhodium,ruthenium,palladium,etc as catalysts.Due to the low abundance and high cost of precious metals,considerable efforts have been devoted to developing new procedures,which are based on earth-abundant metal in the past decade.In this dissertation,firstly,we realized the synthesis of 1,3-dienylsilanes via the hydrosilylation reaction of enynoate with silanes under Pt or Ru catalysis.Next,we discussed the regioselective hydrosilylation reaction of alkynes and 1,3-dienes with silanes that relied on the use of copper catalyst and readily available ligand.And a series of synthetic useful vinylsilanes and allylsilanes compounds were prepared by this strategy.Part Ⅰ:Platinum or Ruthenium-Catalyzed Hydrosilylation of EnynoateA regio-and stereoselective hydrosilylation of structurally diverse enynoates with silanes to access different type 1,3-dienylsilanes was accomplished by employing Pt or Ru catalyst.This approach shows several advantages:such as gentle reaction conditions,high regioselectivity,and broad substrate scope.Part Ⅱ:Copper-Catalyzed Anti-Markovnikov Hydrosilylation of Terminal AlkynesAnti-Markovnikov hydrosilylation of terminal alkynes was successfully achieved by using Cu(CH3CN)4PF6 as catalyst and XantPhos as ligand.A wide range of substituted aromatic and aliphatic terminal alkynes underwent this reaction smoothly.It is worth mention that the acetal and ester groups could also be well tolerated within our strategy.This reaction shows outstanding recognition between the internal and terminal triple bonds or between the terminal triple bonds and double bonds.Several control experiments were conducted and a reasonable mechanism was proposed.Besides,in combination with DFT calculation,we provide a proper interpretation of the regioselectivity of this reaction.Part Ⅲ:Copper-Catalyzed Regioselective Hydrosilylation of 1,3-DienesThe 1,2-hydrosilylation and 1,4-hydrosilylation of 1-substituted 1,3-dienes were highly and selectively controlled by tuning the copper catalytic systems.Meanwhile,the 1,4-hydrosilylation reaction of 2-aryl-substituted 1,3-dienes was also successfully implemented.These methods provide an efficient means for the synthesis of structurally diverse allylsilanes.