Thexyldimethylsilyl chloride

To a solution of thexyldimethylsilyl chloride (11 mmol) and ImH (15 mmol) in DMF (5 ml) was added the alcohol (11 mmol) at ambient temperature. After being stirred at ambient temperature for 16 h, the mixture was diluted with hexane. The hexane phase was washed with water (2x), and then dried. Concentration followed by distillation (Kugelrohr) gave the silyl ether (86-93%). 

Thexyldimethylsilyl chloride (bp 55-56 01.3 kPa) and the corresponding tri-flate have been recommended152 as cheaper substitutes for rm-buty[dimethylsilyl chloride and /er/-butyldimethylsilyl triflate. Thexyldimethylsilyl ethers are formed at comparable rates and they are at least 2-3 times more stable than TBS ethers to acid and base hydrolysis but they introduce unwelcome clutter to NMR spectra, Thexyldimethylsilyl ethers are usually prepared by reaction of the substrate with thexyldimethylsilyl chloride in pyridine151 or in DMF in the presence of imidazole.153... 

Thexyldimethylsilyl chloride is a liquid and is less expensive then TBSCL Furthermore, ROTDS ethers react more slowly under hydrolytic conditions than do RO-TBS ethers. 

Silylating Agent for Protection of Alcohols. Thexyldimethylsilyl chloride (TDS-Cl) was first introduced as a more easily prepared alternative to the more commonly used f-butyl-dimethylsilyl chloride for the protection of alcohols.Direct silylation of 1° and 2° alcohols occurs upon treatment with TDS-Cl and imidazole in DMF as illustrated by the protection of 1-butanol (1) and cyclohexanol (3) to form the corresponding silyl ethers (eqs 1 and I) Phenols can also be protected using TDS-Cl and imidazole. Typical solvents for the formation of silyl ethers using TDS-Cl include DMF, THF, or CH2CI2. ... 

In an example of a 2° alcohol being protected in the presence of another 2° alcohol, diol 10 was selectively protected with thexyldimethylsilyl chloride to produce the monosilyl ether 11 (eq 6). Other exan5>les similarly employed thexyldimethylsilyl chloride as the reagent of choice for selective protection... 

Thexyldimethylsilyl chloride has also been used to produce a new protecting group, thexyldimethylsiloxymethyl chloride, via a two-step synthetic process. Ethylthiomethanol 12 was converted to the IDS ether followed by treatment with sulfuryl chloride to produce thexyldimethylsiloxymethyl chloride 13 (eq 7). Siloxymethyl chloride 13 was used to protect 1°, 2°, and 3° alcohols and phenols, and the protecting group was easily removed by treatment with TBAF in THF or EtaNF in CHsCN. ... 

In a related example, 5-methyl-5-phenylsulfoximine (16) was treated with thexyldimethylsilyl chloride and pyridine thaf after aqueous workup, yielded iV-silylated sulfoxitnine (17) in 79% yield (eq 8).i ... 

Preparation of a-Silyl Ketones. SAMP- and RAMP-hydra-zones of methyl ketones have been converted into a-silyl ketones using thexyldimethylsilyl chloride.For example, the SAMP-hydrazone of 2-butanone 18 was deprotonated with LiTMP, and the intermediate anion was treated with thexyldimethylsilyl chloride to form the a-silyl derivative 19 in high yield (eq 9). When other dialkyl ketones were used, thexyldimethylsilyl triflate was required for silylation to occur, but poor regioselectivity was observed. ... 

Formylation of Polyfluoroalkanes. Thexyldimethylsilyl chloride has been used in a formylation reaction via addition of fluorine-containing organozinc intermediates to DMF. When organozinc complex 20 was heated in the presence of thexyldimethylsilyl chloride and DMF, silyl-protected hemiaminal 21 was isolated in 67% yield (eq 10). ... 

Carboxylic acids can also be converted to silyl esters using thexyldimethylsilyl chloride and triethylamine in DMF, diethyl ether, or CH2Cl2. The resultant silyl ester can be hydrolyzed using triethylamine in aqueous acetone. ... 

Neither ketones nor thiols are reactive with thexyldimethylsilyl chloride as the silylating agent. Ketones require the more reactive thexyldimethylsilyl triflate and triethylamine to form silyl enol ethers. But thiols can be converted into the corresponding thiolates, which then undergo silylation with thexyldimethylsilyl chloride to form alkyl silyl thioethers. ... 

Development of a one-pot version of the reaction allowed silyl-protected hemiaminals to be prepared at low temperatures. For example, periluoroheptyl iodide 22 was treated with zinc, thexyldimethylsilyl chloride, and DMF at 0 °C for 2 h to yield the corresponding hemiaminal 23 in 80% yield (eq 11). Although... 

The tris(trimethylsilyl)silyl ligands can be easily modified by reactions with silyl chlorides, as shown with a series of phenylated species Mes Ph SiCl (n = 0-3). Furthermore, triisopropyl, thexyldimethylsilyl, or tert-butyldimethylsilyl substitution are all easily possible.190 The crystallographic characterization of some of the alkali metal derivatives indicates a direct correlation between ligand size and resulting structural parameters. 

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