Synthesis and application of immobilized catalysts for the heterogeneously catalyzed cleavage of the Si-Si bond of chloromethyldisilanes

Article abstract of DOI:10.1002/prac.19973390128

Lewis bases like bis(dimethylamide)phosphoryl compounds (2, 5-7), N-heterocycles (8 and 9) and N,N-dialkylamino-3-propylsilanes bearing alkoxy groups are grafted via siloxane bonds onto silica carriers. The preparation and characterisation of 5-9 are reported. The grafted bis(dimethylamide)phosphoryl compounds (2, 5-7) and N-heterocycles (8, 9) are efficient catalysts for the disproportionation of chloromethyldisilanes into chloromethyloligosilanes and chloromethylsilanes. Grafted N,N-dialkylamino-3-propylsilyl compounds heterogeneously catalyze the Si-Si bond cleavage of the disilanes with hydrogen chloride at 170°C in excellent yields. A mixture of chloromethylmonosilanes is obtained. This reaction is also performed under pressure.