REACTIONS OF LITHIUM HYDRIDOSILYLAMIDES WITH CARBONYL-COMPOUNDS AND MIXTURES OF CARBONYL-COMPOUNDS AND CHLOROTRIMETHYLSILANE

The lithium hydridosilylamides Me-2(H)SiN(Li)R(1: R = CMe3, 2: R = SiM e3) were allowed to react either with the non-enolizable carbonyl comp ounds CH2=C(Me)CHO, PhCHO and Ph2CO followed by trapping with chlorotr imethylsilane (A), or with mixtures of these carbonyl compounds and ch lorotrimethylsilane (B). In the second case the course of the reaction s is determined by the carbonyl compound. The composition of the react ion mixtures is nearly the same according to A and B. Main products in the reactions with the aldehydes are the corresponding imines R'CH=NR (R' = CH2=C(Me), Ph) 3, 4, 8, 9 formed by addition of the hydridosily lamides to the C=O group of the aldehydes and subsequent LiOMe2H elimi nation. Partial hydrosilylation of the aldehydes by the hydridosilanol ate followed by the trimethylsilylation yields the alkoxydisiloxanes R 'CH2OSiMe2OSiMe3 6, 11. In some cases 2 partially reacts under hydrosi lylation to give the alkoxydisilazanes R'CH2OSiMe2NHSiMe3 7, 12. The h ydrosilylation is the preferred reaction of 1 and 2 with benzophenone. The compounds Ph7CHOSiMe2NWR 13, 14 are obtained. This difference in the reaction behaviour of 1 and 2 towards the aldehydes and benzopheno ne is mainly due to steric reasons. Depending on the conditions the im ines Ph2C=NR 20, 21 may be formed. Ph2CHOSiMe2OSiMe3 (22) is a seconda ry product of inline formation. In all reactions of 1 and 2 with the c arbonyl compounds the corresponding alkoxysilanes R'CH2OSiMe3 (5: R' = CH2=C(Me), 6: R' = Ph) and Ph2CHOSiMe3 (15) are generated. Compounds resulting from a reaction of 1 and 2 with chlorotrimethylsilane are pr oduced to minor extent, but only if the molar ratio of amide to carbon yl compounds is not greater than one. The formation of a silanimine in termediate in reaction according to B is not observed.