Preparation Of Organosilicon Grignard Reagents And Its Reactions

Organosilicon Grignard reagents as a new type of silicon metallic bonding compounds,having similar chemical properties with Grignard reagent,are a new method of synthesis of organosilicon compounds,and may have an irreplaceable position in the synthesis of special organosilicon compounds.At present,the researches on silicon metallic bonds only have silicon lithium bonds,silicon sodium bonds and silicon potassium bonds,lacking of researches of silicon magnesium bonds compounds(Organosilicon Grignard reagents).Therefore,in this paper the synthetic conditions and application of Organosilicon Grignard reagents was studied.The detailed studies had been carried out about the two aspects of Organosilicon Grignard reagent.One was the synthesis of Organosilicon Grignard reagents;The other was the reaction of Organosilicon Grignard reagents.Trimethyl silicon magnesium chloride was prepared with trimethyl chlorosilane and magnesium powder as reactant,hexamethylphosphoramide(HMPA)as solvent,chose the suitable reaction temperature,and then added allyl bromide to the reaction system,making Organosilicon Grignard reagents with allyl bromide taking place coupling reaction,trimethyl allyl silane was successfully achieved.Through infrared spectroscopy(FTIR)and nuclear magnetic resonance(NMR)characterized of trimethyl silicon magnesium chloride and trimethylallylsilane.FTIR and NMR results show that trimethyl magnesium chloride containing the structure of Si-Mg and trimethyl allyl silane has the structure of C = C;29Si NMR spectra displayed that there exist a signal peak at 7.22ppM in trimethyl silicon maglesium chluride,13Si NMR spectra displayed that there exist a signal peak at 0.28ppm in trimethylallylsilane.Trimethyl silicon magnesium chloride was prepared with trimethyl chlorosilane and magnesium powder as reactant,hexamethylphosploramide(HMPA)as solvent,chose the suitable reaction temperature,and then added trimethyl chlorosilane to the reaction system,making Organosilicon Grignard reagents with trimethyl chlorosilane taking place coupling reaction,Hexamethyl-disilane was successfully achieved.Through infrared spectroscopy(FTIR)and nuclear magnetic resonance(NMR)characterized of trimethyl silicon magnesium chloride and hexamethyl-disilane.FTIR and NMR results show that trimethyl magnesium chloride containing the structure of Si-Mg;29Si NMR spectra displayed that there exist a signal peak at 7.22ppm in trimethyl silicon magnesium chloride,29Si NMR spectra displayed that there exist a signal peak at-19.76ppm inhexamethyl-disilane.Phenyldimethyl silicon magnesium chloride was prepared with phenyl dimethyl chlorosilane and magnesium powder as reactants,hexamethylphosphoramide(HMPA)as solvent,chose the suitable reaction temperature,and then added excess acid solution to the reaction system,making Organosilicon Grignard reagents hydrolysis,phenyldimethylsilane was successfully achieved.Through infrared spectroscopy(FTIR)and nuclear magnetic resonance(NMR)characterized of phenyldimethylsilane.FTIR and 1H NMR results shows that phenyldimethylsilane contains Si-H structure;the infrared absorption peak of silicon hydrogen bond in phenyldimethylsilane is 2120 cm-1,the 1H NMR chemical shift of silicon hydrogen bond is 4.5 ppm.29Si NMR spectra displayed that there exist a signal peak at-16.80 ppm in phenyldimethylsilane.Diphenylmethyl silicon magnesium chloride was prepared with diphenyl methyl chlorosilane and magnesium powder as reactants,hexamethylphosphoramide(HMPA)as solvent,chose the suitable reaction temperature,and then added excess acid solution to reaction system,making Organosilicon Grignard reagents hydrolysis,diphenylmethylsilane was successfully achieved.Through infrared spectroscopy(FTIR)and nuclear magnetic resonance(NMR)characterized of diphenylmethylsilane.FTIR and 1 H NMR results show that the diphenylmethylsilane contains Si-H structure,the infrared absorption peak of silicon hydrogen bond in diphenylmethylsilane is 2119 cm-1,the 1H NMR chemical shift of silicon hydrogen bond is 5.0 ppm.29Si NMR spectra displayed that there exist a signal peak at-17.15 ppm in diphenylmethylsilane.Triphenylsilicon magnesium chloride was prepared with triphenyl chlorosilane and magnesium powder as reactants,hexamethylphosphoramide(HMPA)as solvent,chose the suitable reaction temperature,and then added excess acid solution to the reaction system,making Organosilicon Grignard reagents hydrolysis,triphenylsilane was successfully achieved.Through infrared spectroscopy(FTIR)and nuclear magnetic resonance(NMR)characterized of triphenyl ilane.FTIR and 1H NMR results show that the triphenylsilane contains Si-H structure,the infrared absorption peak of silicon hydrogen bond in triphenylsilane is 2119 cm-1,the1H NMR chemical shift of silicon hydrogen bond is 5.5 ppm.29Si NMR spectra displayed that there exist a signal peak at-17.98 ppm in triphenylsilane.Trimethyl silicon magnesium chloride was prepared with trimethyl chlorosilane and magnesium powder as reactant,hexamethylphosphoramide(HMPA)as solvent,chose the suitable reaction temperature,and then added excess acid solution to the reaction system,making Organosilicon Grignard reagents hydrolysis,trimethylsilane was prepared.But because of trimethylsilane under normal temperature being gas,the infrared absorption peak of silicon hydrogen bond is 2127cm-1.