引入TBDMS基团提高THAM在超临界二氧化碳中的溶解度

一种新型亲二氧化碳三羟基甲胺(THAM)衍生物设计并合成得到,测试了其313、323、333 K时在超临界二氧化碳中的溶解行为,TBDMS基团的引入有效增加了化合物的二氧化碳溶解性。将实验测定的溶解度数据与Chrastil、KJ、SS、MST、JCF五种不同的热力学理论半经验模型进行了关联,理论值和实验值具有良好的一致性。通过比较五种热力学模型得到Chrastil模型的相关度最好,平均绝对偏差(AARD%)最低为(0.52~2.86)%。此外,还根据Kumar和Johnston理论计算了化合物在超临界相的偏摩尔体积。

Deprotection of t-Butyldimethylsiloxy (TBDMS) Protecting Group with Catalytic Copper (II) Chloride Dihydrate

t-Butyldimethylsilyl (TBDMS) ether can be cleaved upon refluxing in acetone/H2O (95 : 5) in the presence of a catalytic amount of copper (II) chloride dihydrate (5 mmol %).

Selective cleavage of phenolic tert-butyldimethylsilyl ethers using simple organic nitrogen bases

Simple organic nitrogen bases,such as Et_3N,pyridine,DBU,etc.,were found to be convenient and useful reagents for deprotection of TBDMS groups on acidic hydroxyl groups.The efficiency of these bases has an apparent order:1°amine>2°amine>3°amine and aliphatic base>aromatic base.In aqueous DMSO and at room temperature,phenolic TBDMS ethers were removed selectively in the presence of alcoholic TBDMS ethers.And catalytic base can make these reactions complete.This method is high-yielding,fast,clean,saf...

特丁基二甲基硅烷衍生化气相色谱-质谱联用法快速测定苹果汁中的棒曲霉素

运用特丁基二甲基硅烷(TBDMS)衍生化气相色谱-质谱(GC-MS)联用法快速、高灵敏地测定了苹果汁中的棒曲霉素(PAT)。样品用乙酸乙酯-正己烷提取,Carb/C18混合型固相萃取柱净化,TBDMS衍生,GC-MS测定,选择离子监测(SIM)模式,外标法定量。在0.01～1mg/L的范围内线性良好(r>0.98),在2～50μg/kg的添加水平范围内,平均回收率为88%～98%,相对标准偏差(RSD)为5.3%～13.6%,PAT的检出限为0.5μg/kg,测定低限为2μg/kg。该方法快速、高灵敏、准确、专一、耐用,适合对苹果汁中PAT进行确证和定量测定。

乙二醇中羟基单保护的合成方法

以TBDMS-Cl作保护试剂,介绍了一种乙二醇羟基的单保护方法。该方法经工艺改进,收率达88.2%,同时避免了因乙二醇加入过量造成的浪费,降低了工艺成本。此外,解决了NaH使用过程中引起的易燃易爆问题,使该工艺条件更温和、易控制、更易于工业化生产。

An Efficient and Chemoselective Deprotection of tert-Butyldimethyl-silyl Protected Alcohols Using SnCl_2·2H_2O as Catalyst

An efficient and selective method for the deprotection of primary alcoholic tert-butyl-dimethylsilyl (TBS) ethers using SnCl_2·2H_2O as catalyst is described. The reaction conditionsallow primary alcoholic TBS ethers to be desilylated chemoselectively in the presence of phenolicTBS ethers, secondary and tertiary alcolholic TBS ethers, and the extensively used TBDPS-,acetyl-, benzyloxycarbonyl-, p-toluenesulfonyl- and benzyl protective groups.

Synthesis of RNA-Amphiphiles via Atom Transfer Radical Polymerization in the Organic Phase

The combination of hydrophobic polymers with nucleic acids is a fascinating way to engineer the self-assembly behavior of nucleic acids into diverse nanostructures such as micelles,vesicles,nanosheets,and worms.Here we developed a robust route to synthesize a RNA macroinitiator with protecting groups on the 2′-hydroxyl groups in the solid phase using an oligonucleotide synthesizer.The protecting groups successfully solubilized the RNA macroinitiator,enabling atom transfer radical polymerization(ATRP)of hydrophobic monomers.As a result,the RNA−polymer hybrids obtained by ATRP exhibited enhanced chemical stability by suppressing cleavage.In addition,we demonstrated evidence of controlled polymerization behavior as well as control over the molecular weight of the hydrophobic polymers grown from RNA.We envision that this methodology will expand the field of RNA−polymer conjugates while vastly enhancing the possibility to alter and engineer the properties of RNA-based polymeric materials.

N^6-苯甲酰基-2′-叔丁基二甲基硅氧基腺苷-3′-H-膦酸的合成工艺研究

目的研究N^6-苯甲酰基-2′-叔丁基二甲基硅氧基腺苷-3′-H-膦酸的合成工艺。方法以腺苷为起始原料,先对腺苷的嘌呤氨基进行苯甲酰基保护,再分别向腺苷的5′位和2′位引入二甲氧基三苯甲基(DMT)和叔丁基二甲基硅基(TBDMS)保护基,制备得到关键中间体N^6-苯甲酰基-5′-二甲氧基三苯甲氧基-2′-叔丁基二甲基硅氧基腺苷(3)。中间体3与磷试剂2-氯-4H-1,3,2-苯并二氧磷杂环己烷-4-酮反应引入膦酸基团,最后使用二氯乙酸脱除DMT保护基得到目标产物。结果经过5步反应得到了目标化合物N^6-苯甲酰基-2′-叔丁基二甲基硅氧基腺苷-3′-H-膦酸,并利用~1H-NMR、^(31)P-NMR、质谱等方法确证了其结构。本合成工艺的总收率为35.7%,目标化合物的质量分数为98.5%。结论该合成工艺与原有方法相比步骤短,操作简单,具有良好的应用前景。