18402-10-3Relevant academic research and scientific papers
New approach to the synthesis of phosphorodichloridites, phosphorochloridites, and trialkyl phosphites
Majewski, Piotr
experimental part, p. 942 - 955 (2010/01/17)
Different trivalent organophosphorus esters such as phosphorodichloridites, phosphorochloridites, and mixed trialkyl phosphites have been easily synthesized in good yields using a HCl-catalyzed reaction of the corresponding chlorophosphine and alkoxytrimethylsilane by mutual exchange of the alkoxy and chlorine ligand pIIICl/ROSiR′3; exchange reaction). Chemoselectivity of the exchange reaction with primary and secondary alkoxytrimethylsilanes, as well as with alkoxytrimethylsilanes and thioalkoxytrimethylsilanes, respectively, has also been examined. It has been also found that the substitution reaction of chlorophosphines with secondary amine occurs more rapidly than the exchange reaction with ROSiR′ 3.
Silica sulfate, an efficient catalyst for the trimethylsilylation of alcohols
Jin, Tong-Shou,Tian, Ruo-Fei,Liu, Li-Bin,Zhao, Ying,Li, Tong-Shuang
, p. 1823 - 1828 (2007/10/03)
An easy method for the preparation of trimethylsilyl ethers from alcohols and 1,1,1,3,3,3-hexamethyl-disilazane (HMDS) using silica sulfate as a catalyst under mild conditions in excellent yields is described. Copyright Taylor & Francis Group, LLC.
A novel efficient method for the silylation of alcohols using hexamethyldisilazane in an ionic liquid
Mojtahedi, Mohammad M.,Abbasi, Hassan,Abaee, M. Saeed
, p. 1541 - 1544 (2007/10/03)
Benzylic and primary alcohols were protected by hexamethyldisilazane in good to excellent yields at r.t. in 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) ionic liquid. In addition, the ionic liquid was recovered quantitatively and reused efficiently in the next reactions. The protocol was successfully applied to the protection of phenols. Copyright Taylor & Francis Group, LLC.
Phosphomolybdic acid, an efficient catalyst for the trimethylsilylation of alcohols
Jin, Tong-Shou,Li, Yan-Wei,Sun, Guang,Li, Tong-Shuang
, p. 456 - 458 (2007/10/03)
An easy method for the preparation of trimethylsilyl ethers of alcohols with 1,1,1,3,3,3-hexamethyl- disilazane (HMDS) catalysed by phosphomolybdic acid (PMA) under mild conditions has been carried out in excellent yields.
A novel regioselective desulfation method specific to silyl ester of primary sulfate using silylating agents. Selective preparation of secondary alkyl sulfates having a primary hydroxy group
Horibe,Oshita
, p. 181 - 182 (2007/10/03)
The treatment of bis(trimethylsilyl)ester of 1-O-Decylglycerol-2,3-Disulfate with trimethylsilyl-N-trimethylsilylacetimidate (BSA) or (dimethylamino)trimethylsilane caused regioselective desulfation to afford 1-O-decyl glycerol-2-sulfate selectively in good yield. Silylating agents, having nitrogen, seems to be responsible for facilitating trimethylsiloxysulfonyl cation transfer.
Montmorillonite clay catalysis XI1: Protection and deprotection of hydroxyl group by formation and cleavage of trimethylsilyl ethers catalysed by catalysed by montmorillonite K-10
Zhang, Zhan-Hui,Li, Tong-Shuang,Yang, Feng,Fu, Cheng-Guang
, p. 3105 - 3114 (2007/10/03)
An easy preparation of trimethylsilyl ethers of alcohols and phenols with 1,1,1,3,3,3-hexamethyldisilazane(HMDS) catalysed by montmorillonite K- 10 at room temperature has been carried out in excellent yields. Desilyation of trimeylsilyl ethers is catalysed by K-10 in methanol at ambient temperature in high yields.
Clean nitrations: Novel syntheses of nitramines and nitrate esters by nitrodesilylation reactions using dinitrogen pentoxide (N2O5)
Millar, Ross W.,Philbin, Simon P.
, p. 4371 - 4386 (2007/10/03)
In this novel nitration method dinitrogen pentoxide (N2O5) in an inert solvent is used as the nitrating agent, thereby removing the need for strong acids as the reaction medium. The N2O5 cleaves heteroatom-silicon bonds, in silylamines and silyl ethers respectively, to yield the desired energetic groupings (nitramines or nitrate esters respectively) without liberation of acids which would occur with conventional substrates (amines or alcohols). These nitrodesilylation reactions proceed cleanly and in good yield, and the scope of the reaction is illustrated by 29 examples, some of which produce high energy compounds, notably plasticisers and an energetic polymer precursor. These reactions are therefore potentially clean nitrations for the manufacture of energetic compounds which will minimise the impact of this activity on the environment in the future.
An Efficient and Highly Chemoselective Method to Desilylate Silyl Ethers
Lee, Adam Shih-Yuan,Yeh, Hsiu-Chih,Yeh, Ming-Kuo,Tsai, Ming-Hung
, p. 919 - 922 (2007/10/03)
An efficient and highly chemoselective desilylating method is described.Trimethylsilyl ethers (0.25 M) in a CH3OH/CCl4 (1:1) solvent mixture are deprotected to their corresponding alcohols with ultrasound in a commercial ultrasonic cleaning bath.Selective deprotection of tert-butyldimethylsilyl ethers of benzyl alcohols and phenols is achieved under ultrasonic conditions.We deprotected also tert-butyldimethylsilyl ethers of primary alcohols, whereas tert-butyldimethylsilyl ethers of secondary and tertiary alcohols are stable under these conditions. - Key words: Sonochemistry; Ultrasound; Cavitation; Desilylation; Chemoselection; Deprotection.
Liquid-Crystalline D-Glucose Dialkyl Acetals and Dodecyl D-Glucofuranosides
Tietze, Lutz F.,Boege, Kai,Vill, Volkmar
, p. 1065 - 1068 (2007/10/02)
Two new systems of liquid crystalline glucose derivatives 5a-d, 6a, b are prepared, studied and compared with reference compounds.The α- and β-D-dodecyl glucofuranosides 6a, b show smectic A phases.The clearing points of the furanosides are of the same magnitude as those of the pyranosides.The alkyl glucose acetals 5a-d show columnar discotic phases.The clearing points are about 30 deg C lower than those of the corresponding thioacetals. - Key Words: Acetals / Amphiphiles / Carbohydrates / Glucosides / Liquid crystals
Acidity comparison between ion-exchanged clay montmorillonites by using silylation of alcohol
Onaka, Makoto,Hosokawa, Yasutaka,Higuchi, Katsumi,Izumi, Yusuke
, p. 1171 - 1172 (2007/10/02)
Acidities of various ion-exchanged clay montmorillonites in organic media are compared by use of the reaction of a primary alcohol with allyltrimethylsilane. The order of catalytic activities of the montmorillonites coincide with a sequence of hydration enthalpy of exchanged cations in the clays.
