One-Pot Synthesis of N-Boc-2, 5-bis(trimethylsilyl)pyrrolidine

N-Boc-2, 5-bis(trimethylsilyl)pyrrolidine 4 was synthesized from the reaction of N-Boc-pyrrolidine 1 with trimethylsilyl chloride (TMSCl) at optional temperature in one-pot in good yield.

Formation of multiple trimethylsilyl derivatives in the derivatization of 17α-ethinylestradiol with BSTFA or MSTFA followed by gas chromatography-mass spectrometry determination

N,O-bis（trimethylsily）trifluoroacetamide （BSTFA） and N-methyl-N（trimethylsily） trifluoroacetamide （MSTFA） are common derivatization reagents used in the GC-MS analysis of estrogen steroids such as estrone （El） and 17α-ethinylestradiol （EE2）. In this study, three trimethylsilyl （TMS） steroid derivatives, mono- and di-trimethylsilyl EE2 and mono-trimethylsilyl El, were observed during the derivatization of EE2 with BSTFA or MSTFA and/or GC separation. Factors influencing the production of multiple TMS derivatives and their relative abundance were examined. It was found that both methanol and bisphenol A competed with estrogenic esteroids when reacting with silylation reagents, and thus affected the formation of TMS derivatives and their relative abundance in the derivatization products. Methanol was found to be more reactive than bisphenol A with the BSTFA reagent. None of the three solvents tested in this study could prevent the generation of multiple TMS derivatives during the derivatization of EE2 with BSTFA, followed by GC analysis. A similar result was observed using MSTFA as the derivative reagent followed by GC analysis. Thus, the suitability of BSTFA or MSTFA as the derivatization reagent for the determination of E1 and EE2 by GC-MS, under the conditions reported here, is questionable. This problem can be solved by adding trimethylsilylimidaz （TMSI） in the BSTFA reagent as recommended, and the performance of the method has been proved in this study.

Adjusting the solvation structure with tris(trimethylsilyl)borate additive to improve the performance of LNCM half cells

Tris(trimethylsilyl)borate(TMSB) has been intensively studied to improve the performances of lithiumion batteries. However, it is still an interesting issue needed to be resolved for the research on the Li^(+) solvation structure affected by TMSB additive. Herein, the electrochemical tests, quantum chemistry calculations, potential-resolved in-situ electrochemical impedance spectroscopy measurements and surface analyses were used to explore the effects of Li^(+) solvation structure with TMSB additive on the formation of the cathode electrolyte interface(CEI) film in LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/Li half cells. The results reveal that the TMSB additive is easy to complex with Li^(+) ion, thus weaken the intermolecular force between Li^(+) ions and ethylene carbonate solvent, which is benefit for the cycle performance. Besides, the changed Li^(+) solvation structure results in a thin and dense CEI film containing compounds with Si–O and B–O bonds which is favorable to the transfer of Li^(+) ions. As a result, the performances of the LNCM811/Li half cells are effectively improved. This research provides a new idea to construct a high-performance CEI film by adjusting the Li^(+) solvation structures.

TRIMETHYLSILYLATED SILICA AS RHEOLOGY MODIFIER FOR SILICONE RESINS

Trimethylsilylated silica was synthesized. through hydrolytic condensation of tetraethoxysilane followed by trimethylsilylation. Rheological properties of the silicone resin with trimethylsilylated silica as modifier were studied. It turned out that the particle size of silica was important to the rheological behavior of the modified resin. Trimethylsilylated silica of medium particle size shows the strongest tendency of forming physical network in the resin.

Efficient oxidative deprotection of trimethylsilyl,tetrahydropyranyl and methoxymethyl ethers under solvent-free conditions

A mild, efficient and fast method for direct oxidation of trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers to their corresponding carbonyl compounds using trinitratocerium（Ⅳ） bromate （TNCB） supported on NaHSO4.H2O under solvent-free conditions is reported.

Tris(trimethylsilyl) borate as an electrolyte additive for high-voltage lithium-ion batteries using LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2 cathode

The influence of tris(trimethylsilyl) borate (TMSB) as an electrolyte additive on lithium ion cells have been studied using Li/LiCo1/3Ni1/3Mn1/3O2 cells at a higher voltage, 4.7 V versus Li/Li+. 1 wt% TMSB can dramatically reduce the capacity fading that occurs during cycling at room temperature (RT) and elevated temperature (60 degrees C). After 150 cycles at 1 C rate (1 C= 278 mAh/g), the capacity retention of Li/LiCo1/3Ni1/3Mn1/3O2 is up to near 72% in the electrolyte with TMSB added, while it is only about 35% in the baseline electrolyte. The electrochemical behaviors, the surface chemistry and structure of Li/LiCo1/3Ni1/3Mn1/3O2 cathode are characterized with charge/discharge test, linear sweep voltammetry (LSV), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), thermal gravimetric analyses (TGA), scanning electron microscope (SEM) and transmission electron microscopy (TEM). These analysis results reveal that the addition of TMSB is able to protectively modify the electrode CEI film in a manner that suppresses electrolyte decomposition and degradation of electrode surface structure, even though at both a higher voltage of 4.7 V and an elevated temperature of 60 degrees C. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

XPS STUDIES ON SURFACE MODIFIED POLY [1-(TRIMETHYLSILYL)-1-PROPYNE] MEMBRANES Ⅱ SURFACE MODIFICATION BY BROMINE VAPOR

Surface modification of poly [1-(trimethylsilyl)-1-propyne] (PTMSP) membranes bybromine vapor has been studied. It is shown that Br/C atomic ratio at the surfaces increased withthe time of bromination until about 60 min, then it reached a plateau. The results of XPS and IRstudies indicated that the addition of bromine to double bonds and the replacement of H on CH_3 bybromine had taken place so that a new peak at 286.0 eV (C--Br)in C_(1s) spectra and some newbands, e. g. at 1220 and 580cm^(-1) in IR spectra were formed. The fact,t Po_2, permeability ofoxygen, decreased and α_(O_2/N_2), separation factor of oxygen relative to nitrogen, increased withbromination time, shows that surface modification of PTMSP by bromine may be an efficient approach to prepare PTMSP membranes used for practical gas separations.

Enhanced efficiency and stability in Sn-based perovskite solar cells by trimethylsilyl halide surface passivation

Lead free tin perovskite solar cells(PKSCs)are the most suitable alternative candidate for conventional lead perovskite solar cells.However,the efficiency and the stability are insufficient,mainly because of the poor film quality and numerous defects.Here we introduce an efficient strategy based on a simple trimethylsilyl halide surface passivation to increase the film quality and reduce the defect density.At the same time,a hydrophobic protective layer on the perovskite surface is formed,which enhanced the PKSCs’stability.The efficiency of the solar cell after the passivation was enhanced from 10.05%to 12.22%with the improved open-circuit voltage from 0.57 V to 0.70 V.In addition,after 92 days of storage in N_(2) filled glovebox,the modified T-PKSCs demonstrated high stability maintaining 80%of its initial efficiency.This work provides a simple and widely used strategy to optimize the surface/interface optoelectronic properties of perovskites for giving more efficient and stable solar cells and other optoelectronic devices.

GC-MS STUDY ON DIURETICS IN URINE Ⅱ.DETECTION METHOD USING TRIMETHYLSILYLATION

A reliable method is described for the detection of amitoride,triamterene. canrenone and spironolactone in human urine using GC-MS analysis after trimethytsitytation.The mass spectrometric and metabotic features of the compounds are discussed

Studies on Glycosides(Ⅺ)──A Convenient Stereoselective Synthesis of 1-O-Aryl-α-D-glucopyranosides from Glucosyl Trimethylsilyl Ether

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β-水芹烯异构制备α-松油烯的研究

对β-水芹烯酸催化异构制备α-松油烯的工艺进行了研究,结果表明:三甲基溴硅烷(TMSBr)因酸性适中对β-水芹烯表现出良好催化效果,但其对α-蒎烯、β-蒎烯、3-蒈烯、苧烯和异松油烯等单萜烯催化效果不佳;助剂30%(质量分数)H_(2)O_(2)因其所含的水可使TMSBr转化为H+从而催化异构反应进行,并通过对H+的扩散作用减少副反应发生,此外H_(2)O_(2)自身酸性对反应起到辅助催化效应,这3方面特性极大提升了反应效率。β-水芹烯异构制备α-松油烯的较佳工艺条件为:β-水芹烯0.1 mol、TMSBr 0.002 mol、30%H_(2)O_(2)0.1 mol、反应温度100℃、反应时间6 h,此条件下原料转化率为88.4%,产物选择性为94.0%。

Nanocrystalline TiO_2 as an efficient and reusable catalyst for the chemoselective trimethylsilylation of primary and secondary alcohols and phenols

Nanocrystalline TiO_2 was used as an efficient and recyclable catalyst for the chemoselective trimethylsilylation of primary and less hindered secondary alcohols and phenols with hexamethyldisilazane（HMDS）.All reactions were performed under mild and completely heterogeneous conditions in good to excellent yields.

Determination of free fatty acids in rabbit plasma by GC-MS after trimethylsilylation derivatization

In the present study, free fatty acids(FFAs, including palmitic acid, stearic acid, oleic acid, linoleic acid and arachidonic acid) in rabbit plasma were determined by gas chromatography-mass spectrometry(GC-MS) after trimethylsilylation derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide(BSTFA) – trimethylchlorosilane(TMCS) as derivatization reagent. The experimental conditions, including extraction and silylation reaction, were investigated. The method was experimentally validated. The linearity between fatty acids’ peak areas and their concentrations was obtained with the corelative coefficient(r2) all more than 0.999, and the recoveries were between 82% and 111%. The intra-day variations of FFAs’ in plasma samples at different concentrations were all less than 6%. FFA analysis results of 16 rabbit plasma samples showed that the method could be well applied in the determination of plasma samples in vivo. In contrast to the traditional method of FFA derivatization, the established trimethylsilylation method presented simplicity, high specificity, and completely free from the interference of the esterified fatty acid, such as triacylglyceride. The method could be applied for analyzing FFA profiles in the clinical laboratory or pharmacological research.

Enzymatic Enantioselective Synthesis of (R)-2-Trimethylsilyl-2-hydroxyl-propionitrile by Defatted Apple Seed Meal

The enantioselective synthesis of ( R ) 2 trimethylsilyl 2 hydroxyl propionitrile by ( R ) oxynitrilase contained in defatted apple seed meal in a biphasic system was successfully performed. The influences of some factors on the reaction were investigated systematically. Diisopropyl ether was found to be the best for this reaction among all the organic solvents examined. The optimal concentration of defatted apple seed meal, aqueous phase content, concentrations of acetyltrimethylsilane and acetone cyano^hydrin, buffer pH, reaction temperature were 4% ( W/V ), 23% ( V/V ), 20 mmol·L -1 , 40 mmol·L -1 , pH=5 0 and 40 ℃, respectively, under which the initial reaction rate, substrate conversion and product enantiomeric excess were 9 4 mmol·L -1 ·h -1 , 99% and >99%, respectively.

N,O-Bis(trimethylsilyl)acetamide/N-hydroxysuccinimide ester(BSA/NHS) as coupling agents for dipeptide synthesis

A method using N,O-bis（trimethylsilyl）acetamide/N-hydroxysuccinimide ester（BSA/NHS） as coupling agents for dipeptide synthesis is descried. The coupling reaction between N-hydroxysuccinimide（NHS）esters and amines could be performed under mild conditions with N,O-bis（trimethylsilyl）acetamide（BSA） as coupling reagent and no additional acid/base is required. All byproducts and excessive reactants are water soluble or hydrolysable and easy to eliminate through water-washing at the purification stage.Moreover, all the reactants are inexpensive and widely used in conventional drug production.

锂电池电解液功能添加剂乙二醇(双丙腈)醚的合成研究

提供了一种高效的乙二醇(双丙腈)醚的合成方法,该方法是在催化剂二-(三甲基硅基)胺基锂(20%四氢呋喃溶液)作用下,以乙二醇和丙烯腈为原料一步法反应得到。该反应条件温和,反应温度控制在35℃左右,反应结束后,先用稀硫酸调节pH值至6左右,然后减压蒸馏除去未反应的丙烯腈、四氢呋喃以及少量水分,再经过高真空精馏即可得到纯度大于99.9%的产品乙二醇(双丙腈)醚。该合成方法的物质的量收率以乙二醇计大于90%,并且中间体单醚经回收套用后,物质的量收率可达到95%,该工艺既可满足作为高品质锂离子电池电解液添加剂的应用要求,又可用于大规模的工业化生产。

Application of carbene reactive intermediates in organic synthesis——Ⅲ.Reaction of difluorocarbene with trimethylsilyl enol ethers

The addition of difluorocarbene generated from phenyl(trifluoromethyl)mercury and anhydrous sodium iodide,with trimethylsilyl enol ethers derived from cyclohexanone,cycloheptanone, 3-pentanone and acetophenone was described.The corresponding 2,2-difluoro-1-trimethylsilyloxy- cyclopropanes were obtained in good yields.The thermal stability of these cyclopropyl derivatives was affected by the molecular strain and the nature of their substituents.Thus,1-trimethylsilyloxy- cyclopentene reacted with difluorocarbene to give only 2-fluoro-2-cyclohexen-1-one instead of the expected 1-trimethylsilyloxy-6,6-difluorobicyclo[3.1.0]hexane,and a mechanism for its formation was proposed.

3-(三甲基硅基)丙炔酰氯的合成研究

3-(三甲基硅基)丙炔酰氯是合成防治小麦全蚀病杀菌剂硅噻菌胺的重要中间体,以丙炔醇■为起始原料,经硅烷化后与格氏试剂发生三甲基硅基交换得3-(三甲基硅基)丙炔醇■经2,2,6,6-四甲基哌啶氧化物(TEMPO)催化氧化得3-(三甲基硅基)丙炔醛■经氯代得3-(三甲基硅基)丙炔酰氯■,纯度98%(GC),总收率78%。产物经~1H NMR、^(13)C NMR和MS结构表征确证。该合成方法反应条件温和、收率较高、经济性好、便于生产,具有工业化前景。

六甲基二硅胺烷在有机合成领域的研究进展

六甲基二硅胺烷在光刻涂胶工艺、薄膜制备、电化学、有机合成等领域应用广泛,综述了其在有机合成领域的研究进展,并展望了其发展趋势。