C-bonded silanetriols

Our interest in this area has been in synthesizing a variety of silanetriols where silicon is bonded to carbon, nitrogen, or oxygen in order to assess their relative stabilities as well as the differences in their reactivities. The C-bonded silanetriol tBuSi(0H)3 (12) was synthesized from the commercially available /BuSiCb (Scheme 3) [23]. The bulky t-butyl group afforded the desired steric protection needed to avoid the self-condensation. However, it should be mentioned that the hydrolysis of tBuSiCla in the presence of KOH leads to the isolation of the primary condensation product of the /-butylsilanetriol, [tBuSi(OH)2]20 [2]. 

In the case of the 0-bonded silanetriol (2,4,6-tBu3C6H2)OSi(OH)3 (18) containing a Si04 tetrahedron, this resonance is observed at -83.7 ppm. For the only Si-bonded silanetriol (Me3Si)3SiSi(OH)3 (5) this resonance appears at -25.8 ppm. Thus, the high-field shifts for the silanetriols increase in the following order Si-SiOs < C-SiOs < N-SiOs < O-SiOs. 

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