N-trimethylsilyldiethylamine

Treatment of the allylic sulfoxide 1227 a with diisopropylethylamine (DIPEA) or of 1227 b with N-trimethylsilyldiethylamine 146 and TMSOTf 20 leads in ca. 90% yield to the quaternary amino derivatives 1228 and 1229 and HMDSO 7 [36] (Scheme 8.15). Tetramethylene sulfoxide 1230 reacts with silylated thymine 1231 in the presence of three equivalents of TMSOTf 20 to give the 4 -thio-nucleoside analogue 1232 and HMDSO 7 [37]. Other silylated pyrimidine, pyridine, and purine bases react analogously with cyclic sulfoxides to give 4 -thio-nucleoside analogues [37, 37a, 38]. 

N-Trimethylsilyldiethylamine (TMSDEA) is a strongly basic silylating reagent and is particulady usehil for derivatizing low molecular weight acids. The reaction by-product, diethylamine, is volatile enough to be easily removed from the reaction medium. 

Among the main commercial silylation agents, we can mention N,0-bis(tri-methylsilyl)trifluoroacetamide (BSTFA) to which is generally added 1% of trimethyl-chlorosilane (TMCS), the latter playing the role of a catalyst in the reaction, n-methyl-n-(trimethylsilyl)trifluoroacetamide (MSTFA), n-trimethylsilyldiethylamine (TMSDEA), N,0-bis(trimethylsilyl)acetamide (BSA), generally used in mixture with trimethylchlorosilane, and l-(trimethylsilyl)imidazole (TMSl). These molecules are presented in Figure 1.2. 

Trimethylpyridine, 61, 62 N-Trimethylsilylamides, 204 Trimethylsilyl azide, 276, 542 Trimethylsilylcarbene, 544 Trimethylsilyl cyanide, 542-543 Trimethylsilyldiazomethane, 543-544 Trimethylsilyldiethylamine, 544-545 Trimethylsilyl enol ethers, 125, 538 N-(Trimethylsilyl)glycine trimethyl silyl... 

Reaction with trimethylsilyldiethylamine Trimethylsilyl esters of N-trimethylsilylamino acid 28, 29... 

Coad [82] on the formation of derivatives in the column by consecutive insertion into it of (1) a sample of the compound to be analysed and (2) a reagent, suggested using this method to form TMS derivatives. The method was applied to the analysis of polyols, acids and oxyacids. As the donor of the TMS group a mixture of N,0-bis(trimethylsilyl)-acetamide, trimethylsilyldiethylamine and hexamethyldisilazine was used. Fig. 1.14 shows a chromatogram of the TMS derivatives of polyols, obtained in the analysis of a mixture of polyols performed in accordance with the method proposed by Esposito... 

Typical vapor phase silylating agents used in top surfaee imaging systems include dimethylsilyldimethylamine (DMSDMA), trimethylsilyldimethylamine (TMSDMA), and trimethylsilyldiethylamine (TMSDEA). Typical liquid phase silylating agents used in top surfaee imaging systems inelude 1,1,33,5,5-hexamethylcyclotrisilazane and bis(dimethylamino)dimethylsilane with N-methyl-2- pyrrolidone (NMP) as a diffusion promoter. Typical polymer resins include polyvinyl phenol and novolac/diazoquinone polymer resins. 

Silylation of Amines. While there are several effective methods for preparation of Af-(trimethylsilyl)amines, only a few successful procedures for Af,Af-bis(trimethylsilyl)alkylamines synthesis have been reported. If silylation of ethylamine is attempted with trimethylsilyl chloride, only 13% of NJ -bis(trimethylsilyl)ethylamine is obtained in addition to the major product iV-(trimethylsilyl)ethylamine. However, N,N-bis(trimethylsilyl)amines can be prepared by silylation of monosi-lylamines with trimethylsilyldiethylamine in the presence of catal3Tic ammonium sulfate or ammonium chloride. Another convenient method for the preparation of Af,A-bis(tri-methylsilyl)alkylamines has recently been reported. There trimethylsilyldiethylamine has been found to be effective in the conversion of primary amines, especially aromatic systems, and their monotrimethylsilyl derivatives into the corresponding bistrimethylsilyl products in high yields. For example, when isopropyl amine (or aniline) is refluxed with 1.1 equiv of trimethylsilyldiethylamine and 1.15 equiv of methyl iodide in toluene for 4 h, bis(trimethylsilyl)isopropylamine [or bis(trimethylsilyl)aniline] can be obtained in 99% yield (or 88% yield based on GC) (eqs 16 and 17). 

---