General and efficient method for the synthesis of alkoxymethylsilanes

Abstract

Although alkoxymethylsilanes serve as useful building blocks, various efforts to synthesize them by substitution reaction with an alkoxide ion at the carbon adjacent to the silicon failed. To solve this synthetic problem a new route which is very simple to perform was developed. Bromination of (methoxymethyl)trimethylsilane by using N‐bromosuccinimide/2,2′‐azobisisobutyronitrile (NBS/AIBN) was followed by a substitution by alcohols in the presence of triethylamine to give the corresponding [alkoxy‐­(methoxy)methyl]trimethylsilanes. These acetals can be used directly for the next reduction with di‐isobutylaluminium hydride (DIBAL‐H) or Et3SiH/BF3·OEt2 to give alkoxymethylsilanes in good to moderate yields. The success of the substitution reaction with the alcohols suggests that the mechanism is of somewhat SN1 by nature and formation of the cationic intermediate seems to release the steric hindrance around the carbon, allowing the attack of alcohols. Copyright © 1999 John Wiley & Sons, Ltd.

Intramolecular Participation in Alkoxycarbenium Ion Pools

“…α-Silyl ethers 4a − d were synthesized according to the method that we reported previously (Scheme ) . Bromination of (methoxymethyl)trimethylsilane by NBS followed by a substitution with a methoxyalkyl alcohol gave the corresponding [methoxyalkoxy(methoxy)methyl]trimethylsilanes.…”

Synthesis and Fluoride-Promoted Wittig Rearrangements of α-Alkoxysilanes

“…Upon beginning our study, we were quick to realize that few general methods exist for the synthesis of α-alkoxysilanes with more complexity than that of the (TMS)methyl ethers. , (Perhaps one reason for the lack of progress in this area.) Although the substituted α-hydroxysilanes ( 1 ) (Scheme ) are easily obtained via retro-Brook rearrangement, the alkylation of these alcohols in situ 11 or under basic conditions proved difficult .…”