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.
Preconcentration/separation of Co（II）, Fe（III）, Pb（II）, Cr（IIl）, Cu（II） and Cd（II） ions using bis（5-bromo- 2-hydroxy-benzaldehyde）-2-methy1-1,5-pentane diimine （BBHBPDI） on SDS coated alumina has been ...Preconcentration/separation of Co（II）, Fe（III）, Pb（II）, Cr（IIl）, Cu（II） and Cd（II） ions using bis（5-bromo- 2-hydroxy-benzaldehyde）-2-methy1-1,5-pentane diimine （BBHBPDI） on SDS coated alumina has been reported. The influences of the analytical parameters including pH, ligand and SDS amount, type and concentration of eluent and sample volume on metal ions recoveries were investigated. At optimum values of all variables the relative standard deviation are between 2.5-2.7 and preconcentration factor was 375, while recoveries for all understudy metal ions are higher than 95%, determination limits are between 1.5-2.7. The method has been successfully applied to determination of Co（II）, Fe（III）, Pb（II）, Cr（III）, Cu（II） and Cd（II） ions content in some real samples.展开更多
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 amine...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.展开更多
以三(三甲基硅基)肼锂和对甲苯磺酰叠氮为起始原料,合成了高活性的1,2‐二(三甲基硅基)二氮烯(BSD),进一步利用其二聚反应,合成了1,1,4,4‐四(三甲基硅基)四氮烯(TST),总收率约5.0%,通过核磁共振谱、红外光谱、元素分析和紫外‐可见吸...以三(三甲基硅基)肼锂和对甲苯磺酰叠氮为起始原料,合成了高活性的1,2‐二(三甲基硅基)二氮烯(BSD),进一步利用其二聚反应,合成了1,1,4,4‐四(三甲基硅基)四氮烯(TST),总收率约5.0%,通过核磁共振谱、红外光谱、元素分析和紫外‐可见吸收光谱对BSD和TST的结构进行了表征。通过量子化学计算方法研究了BSD二聚反应的机理。结果表明,发现其先异构化为1,1‐二(三甲基硅基)二氮烯中间体,然后两个中间体相互作用形成TST,两个过程分别需要高达103.0 k J·mol^(-1)和114.3 k J·mol^(-1)的活化能,该理论结果与高温条件有利于BSD转化为TST的实验现象一致。展开更多
基金the National Natural Science Foundation of China (No 29772004).
文摘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.
文摘Preconcentration/separation of Co（II）, Fe（III）, Pb（II）, Cr（IIl）, Cu（II） and Cd（II） ions using bis（5-bromo- 2-hydroxy-benzaldehyde）-2-methy1-1,5-pentane diimine （BBHBPDI） on SDS coated alumina has been reported. The influences of the analytical parameters including pH, ligand and SDS amount, type and concentration of eluent and sample volume on metal ions recoveries were investigated. At optimum values of all variables the relative standard deviation are between 2.5-2.7 and preconcentration factor was 375, while recoveries for all understudy metal ions are higher than 95%, determination limits are between 1.5-2.7. The method has been successfully applied to determination of Co（II）, Fe（III）, Pb（II）, Cr（III）, Cu（II） and Cd（II） ions content in some real samples.
基金financially supported by the National Science and Technology Major Project of China(No.521042)
文摘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.
文摘以三(三甲基硅基)肼锂和对甲苯磺酰叠氮为起始原料,合成了高活性的1,2‐二(三甲基硅基)二氮烯(BSD),进一步利用其二聚反应,合成了1,1,4,4‐四(三甲基硅基)四氮烯(TST),总收率约5.0%,通过核磁共振谱、红外光谱、元素分析和紫外‐可见吸收光谱对BSD和TST的结构进行了表征。通过量子化学计算方法研究了BSD二聚反应的机理。结果表明,发现其先异构化为1,1‐二(三甲基硅基)二氮烯中间体,然后两个中间体相互作用形成TST,两个过程分别需要高达103.0 k J·mol^(-1)和114.3 k J·mol^(-1)的活化能,该理论结果与高温条件有利于BSD转化为TST的实验现象一致。
