Synthesis of α-(Alkoxysilyl)acetic esters. A route to 1,2 diols

Recent progress in the catalytic carbene insertion reactions into the silicon–hydrogen bond

“…a). 19,20 In this work, the synthesis of a-(alkoxysilyl)acetic esters was carried out using a slow addition of adiazoesters into a mixture of chlorosilane and catalytic amounts of Rh2(OAc)4, followed by the nucleophilic substitution on the Si-Cl bond using ROH to form the desired a-alkoxysilanes in good yields (up to 82%), as shown in Scheme 2, eq. a.…”

“…Landais described an easier route to synthesize a-(alkoxysilyl)acetic esters and their utilization. 20,22 As previously disclosed using Rh catalysis (Scheme 2), the synthetic pathway involved a two-step sequence carried out in one-pot: rhodium catalyzed Si-H bond insertion of a metal carbene, followed by a-alkylation of the esters. The key step of this work, however, was then carried out in the same manner as before, but in the presence of a copper catalyst prepared in situ from Cu(OTf)2 and an easily available Schiff-base (Scheme 23).…”

Silylacetic Esters: Enolate Reactions and Polyol Preparation

“…Bearing in mind that we ultimately wished to oxidize the silicon, it had to bear at least one alkoxy or aryl substituent that would allow oxidation by Tamao's or Fleming's method, respectively. Four α-silylacetates were prepared from ethyl diazoacetate by the methods of Doyle 16 and Landais . The silyl substituents included −SiMe 2 Ph, −SiMePh 2 , −SiMe 2 (O−Pr- i ), and −SiMe(OEt) 2 .…”

Synthesis of Benzyltributylstannanes by the Reaction of N-Tosylhydrazones with Bu3SnH

“…The nucleophilic diazo carbon atom interacts with tributyltin hydride to form the tin anion complex B , followed by [1,2]-H migration to afford the product with the extrusion of nitrogen gas. An alternative pathway involves formation of carbene intermediate C followed by the formation of zwitterionic intermediate D and [1,2]-H migration to complete the formal carbene insertion into the Sn–H bond. , With the currently available experimental evidence it is not possible to distinguish these two mechanisms. To gain insights into the mechanistic details of this stannylation process, the reaction of 1b was carried out in the presence of 10 equiv of 1-methoxy-4-vinylbenzene in order to test whether a free carbene intermediate was involved.…”

“…The direct substitution reaction of alkyl halides with trialkylstannyl anion represents a straightforward approach (Scheme c) . In addition, it was reported that the reaction of diazo compounds with Bu 3 SnH gave alkylstannane products through carbene insertion, but the studies were mainly focused on mechanistic aspects of the reaction . Tributyltin radical addition to alkenes has also been reported .…”