Ethyl triethylsilyl

The Cu-catalysed ring expansion of 2-substituted 1,3-oxathiolanes with ethyl (triethylsilyl)diazoacetate affords 2,3-disubstituted 1,4-oxathianes with variable diastereoselectivity the intermediacy of a Cu carbene and of a S-ylide is proposed <02CC346>. 

Ethyl triethylsilyl and ethyl triethylgermyl tellurium reacted with triethylstannane at 20° to produce triethylsilyl(-germyl) triethylstannyl tellurium5 6. 

Triethylsilyl Triethylstannyl Tellurium6 A two-necked, round-bottom flask fitted with a reflux condenser and a nitrogen inlet tube is flushed with nitrogen and charged with 7.14 g (35 mmol) of triethylstannane and 9.5 g (35 mmol) of ethyl triethylsilyl tellurium. The mixture is heated to 35" to initiate the reaction, the flask is cooled when the reaction becomes too vigorous. The reaction is allowed to preceed for 2 h. The resultant mixture is fractionated in a current of nitrogen under reduced pressure yield 14.2 g (91%) b.p. 109-11271 torr. 

When diethyl tellurium was heated with triethylsilane at 200° for seven hours, or with triethylgermane at 140° for seven hours, the Te — C bond was cleaved, ethane liberated, and mixtures of ethyl triethylsilyl tellurium/bis[triethylsilyl] tellurium or ethyl triethylgermyl telluriumlbis[triethylgermyl] tellurium were formed6. However, triethylstannane and diethyl tellurium yieled only bis[triethylstannyl] tellurium even at 20° 5 6. 

Diethyl tellurium, when heated with triethylsilane or triethylgermane at 200° or 140°, respectively, for seven hours, yielded ethyl triethylsilyl tellurium or the corresponding germanium compound3,4. 

Ethyl triethylgermyl tellurium and ethyl triethylsilyl tellurium reacted with trieth-ylstannane at 20c forming diethyl tellurium and triethylstannyl triethylsilyl (or -germylj tellurium4... 

Telluran Ethyl-triethylsilyl- E12b, 192 (R2Te - RTe-SiR3)... 

Silyl oxazoles 55 have been used as precursors to 4-halooxazoles 56, which can then serve as coupling partners in Pd-catalyzed Sonogashira coupling reactions <2000SL692>. The silylated oxazole 55 was prepared in good yield by a Huisgen oxazole synthesis which involved a rhodium-catalyzed reaction between ethyl (triethylsilyl)diazoacetate 54 and benzonitrile (Scheme 7). 

Ethyl triethylsilyl tellurium (11% b.p. 53°/l torr) was similarly prepared by heating the reactants at 200°. Bis[triethylsilyl tellurium and bis[triethylgermyl] tellurium are also formed in these reactions . ... 

Ducept and Marsden described a general synthesis of 5-ethoxy-2-substituted 4-(triethylsilyl)oxazoles 176 from the rhodium(II)octanoate-catalyzed diazo-transfer reaction of ethyl (triethylsilyl)diazoacetate 175 and nitriles (Scheme 1.48). The reaction conditions tolerate a wide variety of functional groups on the nitrile, including alkyl, aryl, heteroaryl, vinyl, carbonyl, sUyloxy, and dialkylamino. Desilylation of 176 with TBAF afforded the corresponding 2-alkyl(aryl)-5-ethoxy-oxazoles 177, which are normally inaccessible from diazoesters using conventional rhodium-carbene methodology. The authors noted that carbonyl groups in the 2 position of 176 are not compatible with TBAF deprotection. 

CjjHjoOioSi 115437-18-8) see Paclitaxel [(triethylsilyl)oxy]acetic acid ethyl ester (C oH220jSi) see Paclitaxel c -3-(triethylsilyloxy)-4-phenyl-2-azetidinone (Ci3H23N02Si) see Paclitaxel trifluoroacetic anhydride... 

Surprisingly, a-cyanoacrylic acid is reported to react spontaneously with triethylsilane in the absence of any additional acid to give a quantitative yield of the triethylsilyl ester of a-cyanopropionic acid.236 Ethyl a-cyanoacrylate requires the presence of trifluoroacetic acid to undergo reduction to ethyl 2-cyanopropionate.236 Many of these reductions are highly stereoselective. For example, treatment of... 

Moreover, the formation of enoxy-silanes via silylation of ketones127 by means of N-methyl-N-TMS-acetamide (1 72) in presence of sodium trimethylsilanolate (173) was reported in 1969 and since then, the use of silylating reagents in presence of a catalyst has found wide appreciation and growing utilization as shown in recent papers128-132 (Scheme 27). Diacetyl (181) can be converted by trifluoromethylsul-fonic acid-TMS-ester (182) into 2,3-bis(trimethylsiloxy)-l, 3-butadiene (7treatment with ethyl TMS acetate (7 5)/tetrakis(n-butyl)amine fluoride l-trimethylsiloxy-2-methyl-styrene (i<56)130. Cyclohexanone reacts with the combination dimethyl-TMS-amine (18 7)/p-toluenesulfonic acid to 1-trimethylsiloxy-l-cyclohexene (iSS)131. Similarly, acetylacetone plus phenyl-triethylsilyl-sulfide (189) afford 2-triethylsiloxy-2-pentene-4-one (790)132. ... 

O-triethylsilyl-lO-deacetylbaccatin III (CMHS(lOl0Si 115437-18-8) see Paclitaxei f(tricthyIsilyl)oxy (acetic acid ethyl ester (CioH22OySi) see Paclitaxei cis-3-(tricthylsilyloxy)-4-phenyl-2-azetidinonc (C15H21N02Si) see Paclitaxei trilluoroacetic anhydride... 

When a solution of diethylaluminio triethylsilyl tellurium in hexane was kept overnight at 20c, polymeric ethyl aluminum telluride remained in the flask after all volatile materials had been removed by vacuum distillation2 3. 

Lithium triethylsilanetellurolate, prepared from bisftriethylsilyl] tellurium and ethyl lithium, reacted with an excess of chlorobutane to form butyl triethylsilyl tellurium2. 

Cycloaddidons of 2-triethylsilyl- and 2-tributylstannyl-13-butadienes (172) to ethyl acrylate and methyl vinyl ketone also proceeded with moderate regioselectivities which could significantly enhanced by Lewis acid catalysis in favor of products (174) (Scheme 41, Table 2). The resulting cyclo-hexenylstannanes (174 M = SnBua) show potential for C—C coiq>ling reactions. 

Abbreviations Ac acetyl AIBN azobisisobutyronitrile All allyl Bn benzyl Bz benzoyl ClAc chloroacetyl DAST diethylaminosulfur trifluoride DBU l,8-diazabicyclo[5.4.0]-undec-7-ene DDQ 2,3-dichloro-5,6-dicyano-/)-benzoquinone DMDO dimethyldioxirane DMTST dimethyl(methylthio)sulfonium trifluoromethanesulfonate Fmoc 9-fluorenyl-methoxycarbonyl HDTC hydrazine dithiocarboxylate IDCP iodonium di-collidine perchlorate Lev levulinoyl MBz 4-methylbenzoyl Me methyl MEK methyl ethyl ketone MP 4-methoxyphenyl NBS iV-bromosuccinimide NIS A-iodosuccinimide Pent n-pentenyl Pfp pentafluorophenyl Ph phenyl Phth phthaloyl Piv pivaloyl PMB 4-methoxybenzyl TBAF tetrabutylammonium fluoride TBDMS tcrt-butyldimethylsilyl TBDPS tert-butyldiphenylsilyl TCA trichloroacetyl TES triethylsilyl Tf trifluoromethanesulfonyl TMS trimethylsilyl Tol 4-methylphenyl Tr trityl Troc 2,2,2-trichloroethoxycarbonyl Ts tosyl. 

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