Triethylsilyl chloride

Et3SiCl, Pyr. Triethylsilyl chloride is by far the most common reagent for the introduction of the TES group. Silylation also occurs with imidazole and DMF arid with dimethylaminopyridine as a catalyst. Phenols, carboxylic acids, and amines have also been silylated with TESCl. 

Scheme 6a presents the synthesis of fragment 15. Intermediate 15 harbors two vicinal stereogenic centers, and is assembled in a very straightforward manner through the use of asymmetric aldol methodology. Treatment of the boron enolate derived from 21 with 3-[(p-methoxybenzyl)oxy]propanal (22) affords crystalline syn aldol adduct 34 in 87 % yield as a single diastereomer. Transamination to the A-methoxy-A-methylamide,20 followed by silylation of the secondary hydroxyl group at C-19 with triethylsilyl chloride, provides intermediate 15 in 91 % yield. 

QHijOjP 122-52-1) see Foscamet sodium Gesirinone 7-O-triethylsilylbaccatin III (C,7H520 Si 115437-21-3) see Paclitaxel 4-triethylsilyl 3-butyn-l-ol triethylsilyl ether (C 4Hj40Si2 160194-28-5) see Rizatriptan benzoate triethylsilyl chloride... 

The 0-silylation reaction of alcohols is important as a protection method of hydroxyl groups. 0-Silylations of liquid or crystalline alcohols with liquid or crystalline silyl chlorides were found to be possible in the solid state. For example, when a mixture of powdered L-menthol (26), ferf-butyldimethylsilyl chloride (27), and imidazole (28) was kept at 60 °C for 5 h, 0-tert-butyldi-methylsilyl L-menthol (29) was obtained in 97% yield [8] (Scheme 4). Similar treatments of 26 with the liquid silyl chlorides, trimethyl- (30a) and triethylsilyl chloride (30b), gave the corresponding 0-silylation products 31a (89%) and 31b (89%), respectively, in the yields indicated [8] (Scheme 4). However, 0-silylation of triisopropyl- (30c) and triphenylsilyl chloride (30d) proceeded with difficultly even at 120 °C and gave 31c (57%) and 31d (70%), respectively, in relatively low yields. Nevertheless, when the solvent-free silylation reactions at 120 °C were carried out using two equivalents of 30c and 30d, 31c (77%) and 31d (99%) were obtained, respectively, in relatively high yields. 

Similarly, 2,2-difluorovinyllithium reacted with triethylsilyl chloride, tribu-tyltin chloride [122], carbon dioxide [123] or aldehydes [124] to give the corresponding 2,2-difluorovinylated derivatives (Scheme 45). 

Silenolates like 180 do react with 2,3-dimethylbuta-l,3-diene in a formal [4+2] fashion and, when the alkoxide 463 is trapped by triethylsilyl chloride, the l-silacyclohex-3-ene... 

DMPU V,iV -dimethyl-A,A -propylene urea TESCl triethylsilyl chloride... 

Cleavage of the benzylidene acetal from 92 was best achieved with anhydrous HCl in methanol diol 91 was produced in 85% yield. Regioselective O-tosylation of 91 could also be efficiently accomplished (79% yield) by the portionwise addition of 1.1 eq. of TsCl, over several hours, to a mixture of the diol, DMAP and Et3N at 0 °C. 0-Silylation of this product with triethylsilyl chloride and DMAP in pyridine again occurred, readily delivering 94 in 89% yield. The nucleophilic displacement of tosylate 94 with sodium iodide in hot acetone thereafter furnished 90 in nearly quantitative yield. 

TESCl triethylsilyl chloride TPAP tetrapropylammonium perruthenate... 

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