酶促合成油酸香茅醇酯的超临界连续反应-分离过程

将固定床动态酶促反应过程和超临界二氧化碳萃取分离过程相耦合,设计并建立了一套超临界相反应分离一体化的实验装置。在该装置上初步考察了反应压力和温度对脂肪酶催化油酸甲酯和外消旋香茅醇酯交换反应的影响。结果表明,我们所建立的反应装置能有效地实现反应分离一体化过程;当体系压力接近二氧化碳的临界压力时反应速率最高;9MPa压力下反应温度为328K时反应转化率最高,而在14MPa压力下反应转化率在308K～328K之间随着温度的升高而增大。     

废弃生物质在超临界水中转化制氢过程的研究

以废弃生物质转化为富氢气体为目的，使用间歇式超临界水反应器，在反应温度773 K～923 K、压力15.5 MPa～34.5 MPa停留时间1 min～30 min和Ca/C摩尔比0～0.56范围内，对木屑在超临界水条件下生成的气体组成及产率进行了考察。实验表明，Ca/C摩尔比和温度对木屑转化的影响较大。当Ca/C摩尔比为0.48时，碳的气体转化率和氢气产率提高了近一倍。温度从773 K提高到923 K，碳的气体转化率由47％提高到76％，氢气产率由4.5 mmol/g上升到6.9 mmol/g。与温度相比，停留时间和压力的影响不大。     

液态及超临界CO_2萃取八角茴香油的研究

本文用液态及超临界CO_2对八角茴香油进行了萃取研究，在萃取压力为20．0～25．0MPa的条件下，详细地考察了临界温度上下萃取温度和解析温度对出油率和油的表观相态的影响，结果表明，萃取温度越高和／或解析温度越低出油率越低；用液体CO_2萃取比用超临界CO_2萃取的出油率要高得多；萃取温度大约在318K以下或解析温度在临界温度以下时，萃取所得八角茴香油都有明显分层现象．     

Separation of Phenylalanine Methylester 5'-Phosphoamidates of d4T Diastereoisomers by Supercritical Fluid Chromatography

采用超临界CO2流体色谱技术,分析d4T-5'-N-磷酰化苯丙氨酸甲酯手性磷的非对映异构体.色谱柱为Hpersil ODS2 (250 mm× 4.6 mm,5 μm),流动相为夹带改性剂甲醇、乙醇和异丙醇的超临界CO2流体.以容量因子、选择性和分离度为指标,考察改性剂、背压和柱温对分离的影响.在甲醇、乙醇和异丙醇3种改性剂中,甲醇为最好的改性剂,其中在7％甲醇改性剂下,该化合物的分离度可达到3.35.在7％甲醇改性剂条件下,考察了压力( 10～20 MPa)和温度(303.15～318.15 K)的影响.在优化的分离条件(改性剂为7％甲醇,流速为2 mL/min,柱温为308.15 K,背压为15 M Pa)下,d4T-5'-N-磷酰化苯丙氨酸甲酯的两种非对映异构体完全达到基线分离,分离时间约15 min.     

分散红60在超临界CO2中的溶解度实验研究

有关分散染料与超临界CO2二元体系的相平衡数据(溶解度)实验测定及模型关联,对超临界流体染色工艺基础研究及工业化至关重要。本文建立了高压溶解度测试实验装置,在温度353～393K、压力15～30MPa条件下,对分散红60在超临界CO2中的溶解度进行了测定。并利用zcan经验公式对实验结果进行关联,关联结果和实验结果吻合较好,最大误差为9.3%。结果表明:体系的压力、温度和混合物密度是影响分散染料在超临界CO2中溶解度的重要因素;可利用zcan经验公式对染料等固体物质在超临界CO2中的溶解度进行关联计算。     

超临界流体色谱法分析非对映异构体d4T-5’-N-磷酰化苯丙氨酸甲酯

采用超临界CO2流体色谱技术,分析d4T-5’-N-磷酰化苯丙氨酸甲酯手性磷的非对映异构体。色谱柱为Hpersil ODS2(250 mm×4.6 mm,5μm),流动相为夹带改性剂甲醇、乙醇和异丙醇的超临界CO2流体。以容量因子、选择性和分离度为指标,考察改性剂、背压和柱温对分离的影响。在甲醇、乙醇和异丙醇3种改性剂中,甲醇为最好的改性剂,其中在7%甲醇改性剂下,该化合物的分离度可达到3.35。在7%甲醇改性剂条件下,考察了压力(10～20 MPa)和温度(303.15～318.15 K)的影响。在优化的分离条件(改性剂为7%甲醇,流速为2 mL/min,柱温为308.15 K,背压为15 M Pa)下,d4T-5’-N-磷酰化苯丙氨酸甲酯的两种非对映异构体完全达到基线分离,分离时间约15 min。     

超临界二氧化碳中布洛芬响应因子的研究

应用高压紫外检测器在线测定了布洛芬在超临界二氧化碳中的响应因子。 考察了温度、压力和CO2密度等参数对它的影响。在温度298-333K、压力9-17MPa范围内超临界CO2中布洛芬的响应因子随CO2密度的增加而线性递减。建立了布洛芬在超临界CO2中响应因子的经验计算式(回归系数r=0．97)，其理论计算结果与实验数据吻合良好，最大误差≤10％。     

在室温离子液体BPBF4中FeCl3电化学性质的研究

以室温离子液体——四氟硼酸正丁基吡啶(BPBF4)为溶剂，在293．15～343．15K温度范围内，测定了不同浓度FeCl3的伏安曲线，估算了在不同浓度和不同温度下Fe^3 的扩散系数D，进而求得了它在不同浓度下的扩散活化能ED，讨论了FeCl3浓度对扩散系数和扩散活化能的影响．     

超临界CO2萃取薰衣草的挥发性组分

1.1样品来源及制备薰衣草：购于新疆远馨香料开发公司。超临界CO2萃取：薰衣草经农用粉碎机粉碎后,用自制的0．5L超临界装置进行萃取(萃取压力：10MPa,萃取温度：321K,萃取时间：120min),得到橙色透明油状物,得率约为2．0％～2．5％,水汽蒸馏：薰衣草粉碎后,经共水蒸馏同时用油水分离器分离精油,3h后收集精油并用无水硫酸钠干燥,得淡黄色油状物,得率约为0．8％～1．0％。     

栀子花挥发油超临界CO2萃取工艺优选分析

采用超临界CO2萃取法,使用正交试验设计方案,以提取率为指标,对萃取温度、萃取压力、分离压力和分离温度等影响因素进行考察。结果表明,超临界CO2萃取法萃取栀子花挥发油成分的最佳工艺条件为：萃取压力15mPa,萃取温度35℃,分离压力15mPa,分离温度25℃。该方法简便、可靠、选择性高,适于工业化生产。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.