Iodotrimethylsilane chlorotrimethylsilane

THF THP TIPS TIPSOTf TMEDA TMS TMSC1 TMSCN TMS I TMSOTf Ts tetrahydrofuran tetrahydropyranyl tri-isopropylsilyl tri-isopropylsilyl trifluoromethanesulphonate AVV,N N -tetramethylethylenediamine trimethylsilyl trimethylsilyl chloride (chlorotrimethylsilane) trimethylsilyl cyanide (cyanotrimethylsilane) trimethylsilyl iodide (iodotrimethylsilane) trimethylsilyl trifluoromethanesulphonate tosyl (p-tolucnesulphonyl)... 

The structurally simplest silicon reagent that has been used to reduce sulphoxides is the carbene analog, dimethylsilylene (Me2Si )29. This molecule was used as a mechanistic probe and did not appear to be useful synthetically. Other silanes that have been used to reduce sulphoxides include iodotrimethylsilane, which is selective but unstable, and chlorotrimethylsilane in the presence of sodium iodide, which is easy to use, but is unselective since it cleaves esters, lactones and ethers it also converts alcohols into iodides. To circumvent these complications, Olah30 has developed the use of methyltrichlorosilane, again in the presence of sodium iodide, in dry acetonitrile (equation 8). A standard range of sulphoxides was reduced under mild conditions, with yields between 80 and 95% and with a simple workup process. The mechanism for the reaction is probably very similar to that given in equation (6), if the tricoordinate boron atoms in this reaction scheme are replaced... 

Dialkyl and alkyl aryl ethers can be cleaved with iodotrimethylsilane ROR -bMe3SiI — Rl-bMe3SiOR. A more convenient and less exjjensive alternative, which gives the same products, is a mixture of chlorotrimethylsilane and Nal. Alkyl aryl ethers can also be cleaved with Lil to give alkyl iodides and salts of phenols in a reaction similar to 10-73. Triphenyldibromophosphorane (Ph3PBr2) cleaves dialkyl ethers to give 2mol of alkyl bromide. ... 

Iodotrimethylsilane formed in situ from the reaction of chlorotrimethylsilane and sodium iodide, also effects the conversion of 2-ene-l,4-diols to 1,3-dienes (equation 16)46. Allylic thionocarbonates on heating with triphenylphosphite undergo deoxygenation (Corey-Winter reaction) to generate olefins47. This procedure has been used for making hexatrienes (equation 17)47b. 

As with other non-metal derivatives, reactivity depends on chain-length, branching and degree of halogen substitution. Individually indexed compounds are f Chloromethylphenylsilane, 2810 f Chlorotrimethylsilane, 1304 f Cyanotrimethylsilane, 1665 f Dichlorodiethylsilane, 1683 f Dichlorodimethylsilane, 0902 f Dichloroethylsilane, 0903 f Dichloromethylsilane, 0470 f Dichloromethylvinylsilane, 1208 f Iodotrimethylsilane, 1306 f Methyltrichlorosilane, 0439 f Trichloroethylsilane, 0854 f Trichlorovinylsilane, 0746... 

Ether cleavage of 2,3-dimethoxyquinoxaline to give 2,3( l//,4//)-quinoxalinedione was performed by treatment with iodotrimethylsilane generated in situ from chlorotrimethylsilane and sodium iodide, albeit in 15—40% yields <1999JHC1271 >. 2,3-Dimethoxyquinoxaline reacts with 2 equiv of butyllithium to furnish 2,2-dibutyl-3-methoxy-1,2-dihydroquinoxaline (Equation 22) <1999T5389>. 

Dialkyl and alkyl aryl ethers are cleaved with iodotrimethylsilane " ROR + MesSil Rl + MesSiOR. A more convenient and less expensive alternative, which gives the same products, is a mixture of chlorotrimethylsilane and... 

In many, but not all, cases iodotrimethylsilane can be replaced by chlorotrimethylsilane plus sodium iodide without changing the course of the reaction. Bromotrimethylsilane and chlorotrimethylsilane plus sodium bromide gave rise to the formation of y-bromides, chlorotrimethylsilane plus lithium chloride yielded y-chlorides. The cyanide ion could not substitute the halides in these reactions. When 1-acetyl-2,2-dimethylcyclopropane (3) was... 

SUylation with HMDS is most commonly carried out with acid catalysis. The addition of substoichiometric amounts of chlorotrimethylsilane (TMSCl) to the reaction mixtures has been found to be a convenient method for catalysis of the silylation reaction. The catalyticaUy active species is presumed to be hydrogen chloride, which is liberated upon reaction of the chlorosi-lane with the substrate. Alternatively, protic salts such as ammonium sulfate can be employed as the catalyst. Addition of cat-al)Tic lithium iodide in combination with TMSCl leads to even greater reaction rates. Anilines can be monosilylated by heating with excess HMDS (3 equiv) and catalytic TMSCl and catalytic Lil (eq 2). Silylation occurs without added Lil however, the reaction is much faster in the presence of iodide, presumably due to the in situ formation of a catalytic amount of the more reactive iodotrimethylsilane. 

Olah GA, Narang SC, GuptaBGB et al (1979) Synthetic methods and reactions. 62. Transformations with chlorotrimethylsilane/sodium iodide, a convenient in situ iodotrimethylsilane reagent J Oig Chem 44 1247-1251... 

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