72190-83-1

Upstream product

• 67-56-1 methanol 
• 78034-87-4 [Bromo-(tris-trimethylsilanyl-methyl)-silanyl]-benzene 
• 78034-86-3 C₁₆H₃₃NO₃Si₄ 
• 72190-78-4 [Iodo-(tris-trimethylsilanyl-methyl)-silanyl]-benzene 

Downstream Products

• 87710-80-3 [Iodo-methoxy-(tris-trimethylsilanyl-methyl)-silanyl]-benzene 
• 139483-48-0 [Fluoro-methoxy-(tris-trimethylsilanyl-methyl)-silanyl]-benzene 
• 139483-54-8 [Chloro-methoxy-(tris-trimethylsilanyl-methyl)-silanyl]-benzene 
• 139483-49-1 C₁₈H₃₅NO₂Si₄ 
• 139483-51-5 C₁₉H₃₈O₃Si₄ 
• 139483-52-6 C₁₉H₃₈O₃Si₄ 
• 139483-50-4 C₁₈H₃₅F₃O₄SSi₄ 

Relevant academic research and scientific papers

Unimolecular Solvolysis of Some Organosilicon Perchlorates and Iodides

Kinetic studies have been made of the solvolysis (mainly the methanolysis) of the highly sterically hindered compounds TsiSiMe2OClO3 , (Me3Si)2(Ph2MeSi)CSiMe2OClO3, TsiSiHPhX (X=I, Br, ONO2), and TsiSiHMeI.The rate of methanolysis of TSiMe2OClO3 is increased by only ca.20percent upon addition of 0.1 M-NaOMe, and further additions of base have smaller effects.Additions of LiCl or LiNO3 cause even smaller rate increases, but in the presence of LiNO3 substantial amounts of TsiSiMe2ONO2 are formed, the amounts being greater than would correspond to the rate increases.Water has a very large accelerating effect, and even with only 1 vol percent of water present the product is very predominantly TsiSiMe2OH.The solvolysis is slower in EtOH and i-PrOH, and occurs only very slowly, if at all, in CF3CH2OH.The methanolysis of (Me3Si)2(Ph2MeSi)CSiMe2OClO3 is slower than that of TsiMe2OClO3.The methanolysis of TsiSiHPhI and TsiHMeI are also accelerated only to a small extent by NaOMe.The above results are interpreted in terms of an SN1 mechanism involving anchimerically assisted ionization of the Si-OClO3 or Si-I bond to give a methyl-bridged cation with unusual solvation requirements.In contrast, the methanolyses of TsiSiHPhX (X = Br or ONO2) are markedly accelerated by base, and it seems that, at least in the presence of base, attack by the nucleophile is involved in the rate-determining step in these cases.

Effects of the substituents Y in reactions of compounds of the type (Me3Si)3CSiH(C6H4Y-p)I. Evidence against the SN2(intermediate) mechanism for methanolysis of (Me3Si)3CSiMe2I and (Me3Si)3CSiHPhI

The rates of methanolysis of the iodides TsiSiH(C6H4Y-p)I (Y MeO, Me, H, Cl, or CF3) in 1/1 v/v MeOH/dioxane have been shown to be increased by electron withdrawal by Y and correspondingly decreased by electron release. This is taken to imply that the methanol is covalently involved in the transition state, and thus that, contrary to an earlier suggestion, the reaction cannot have an SN2(intermediate) mechanism. No explanation can at present be offered for the fact that methanolysis of TsiSiHPhI (like that of TsiSiMe2X with X I, OClO3, or OSO2CF3) is not accelerated by NaOMe whereas that of some other TsiSiHPhX compounds (e.g. X Br, ONO2, or OSO2Me) is so accelerated, with its implications of a duality of mechanism within an SN2 range. The reactions of the iodides TsiSiH(C6H4Y-p)I with KSCN in MeCN are also accelerated by electron withdrawal by Y, whereas those with AgOAc in MeCO2H are accelerated by electron release.

Rate-determining Ionization in Methanolysis of an Organosilicon Halide

Methanolysis of (Me3Si)3CSiPhHI is not significantly accelerated by NaOMe, and so is thought to involve rate-determining ionization of the iodide.