Lodotrimethylsilane

Me3SiI, CHCI3, 25-50°, 12-140 h. lodotrimethylsilane in quinoline (180°, 70 min) selectively cleaves an aryl methyl group, in 72% yield, in the presence of a methylenedioxy group. Me3SiI cleaves esters more slowly than ethers and cleaves alkyl aryl ethers (48 h, 25°) more slowly than alkyl alkyl ethers (1.3-48 h, 25°), but benzyl, trityl, and /-butyl ethers are cleaved quite rapidly (0.1 h, 25°). ... 

CLEAVAGE OF METHYL ETHERS WITH lODOTRIMETHYLSILANE CYCLOHEXANOL FROM CYCLOHEXYL METHYL ETHER... 

Representative Procedure for lodotrimethylsilane and Phosphine Oxide Promoted Clycosylation with Glycosyl Acetate Donors [297]... 

Acid bromides.1 Acid chlorides can be converted to acid hromidcs by, reaction with bromotrimethylsilane (75 -95% yield). Acid iodides can be obtained by use of lodotrimethylsilane. 

Homoallylk ethers. lodotrimethylsilane catalyzes the allylation of acetals and ketals by allylsilanes, with transposition of the allylic group (equation I). It does not catalyze allylation of aldehydes and ketones. Note that TiCI can catalyze both of these reactions (7, 370-371). In this respect, ISi(CH3)3 resembles (CH3)3SiOTf (this volume). 

EPOXIDES Alumina. r-Butyldimethyl-iodosilane. n-Butyllithium-Magnesium bromide. Cyclohexylisopropylamino-magnesium bromide. Dialkylaluminum amides. lodotrimethylsilane. Lithium l-a,a -dimethyldibenzylamide. Nafion-H. Organoaluminum compounds. Pyri-dinium chloride. Raney nickel. Tti-fluoroacetyl chloride, lrimethylsilyl-acctonitrile. Tris(phenylscleno)borane. Zinc iodide. 

REDUCTION, REAGENTS Aluminum amalgam. Borane-Dimethyl sulfide. Borane-Tetrahydrofurane. t-Butylaminoborane. /-Butyl-9-borabicyclo[3.3.1]nonane. Cobalt boride— f-Butylamineborane. Diisobutylaluminum hydride. Diisopropylamine-Borane. Diphenylamine-Borane. Diphenyltin dihydride. NB-Enantrane. NB-Enantride. Erbium chloride. Hydrazine, lodotrimethylsilane. Lithium-Ammonia. Lithium aluminum hydride. Lithium borohydride. Lithium bronze. Lithium n-butylborohydride. Lithium 9,9-di-n-butyl-9-borabicyclo[3.3.11nonate. Lithium diisobutyl-f-butylaluminum hydride. Lithium tris[(3-ethyl-3pentylK>xy)aluminum hydride. Nickel-Graphite. Potassium tri-sec-butylborohydride. Samarium(II) iodide. Sodium-Ammonia. Sodium bis(2-mcthoxyethoxy)aluminum hydride. 

CYCLOPENTENONES Aluminum chloride. 2-(Bromovinyl)trimethylsilane. Di-fjL-carbonylhexacarbonyldicobalt. lodotrimethylsilane. Potassium hydroxide. l-(Trimethylsilyl)-l-(phenylthio)ethylene. 

Synthetic Applications of Cyanotrimethylsilane, lodotrimethylsilane, Azido-trimethylsilane, and Methylthiotrimethylsilane. Groutas, W. G Felker, D, Synthesis 1980, 861,... 

Cleavage of MEM ethers. 2-Methoxyethoxymethyl (MEM) ethers are cleaved by NaI/ClSi(CH,)3 in CHjCN at —20 or 25° in moderate to high yield, lodotrimethylsilane (commercial) is less effective. Fairly selective cleavage of MEM ethers is possible in the presence of lactones, methyl or benzyl ethers, and methyl esters. 

Enol silyl ethers (10, 97). lodotrimethylsilane, generated in situ, is recommended for preparation of the enol silyl ether of acetone. The yield (60% based on chlorotrime-thylsilane) is comparable to that obtained using the more expensive trimethylsilyl triflate. 

Conjugate addition to enones. lodotrimethylsilane can mediate conjugate addition of furanes to a,p-enones via the intermediate 7-iodo enol silyl ether (9, 252-253). The adduct can be isolated as the enol silyl ether or the corresponding ketone (equation 1). ... 

C-AUylated glycopyranosides a-Glycopyranosides or a-glycopyranosyl chlorides arc converted stereoselectively into oc-C-allylated glycopyranosides on reaction with al-lylsilanes catalyzed by trimethylsilyl triflate. lodotrimethylsilane is less effective as the catalyst. 

Alcohols lodotrimethylsilane. Sodium borohydride. Tri-n-butyltin hydride. 

Cleavage of lactones and carbonates. Lactones and carbonates react with bromotrimethylsilane to afford bromocarboxylic acid derivatives (equation I) and bromohydrin trimethylsilyl ethers (equation II), respectively acyclic, aliphatic esters do not react with bromotrimethylsilane. lodotrimethylsilane reacts in an analogous fashion with lactones, but in reaction with ethylene carbonate the main product is 1,2-diiodoethane (equation III). The >-bromocarboxylate derivatives are converted into acid chlorides by reaction with SOCL (equation I). 

---