苊低压加氢合成四氢苊和全氢苊的研究

在间歇式高压反应釜中,采用Ni/g-Al_2O_3加氢催化剂,在较低的反应温度和压力下,进行了苊加氢合成四氢苊和全氢苊的实验研究。考察了反应温度、H_2压力、催化剂用量和反应时间对苊转化率、四氢苊和全氢苊选择性的影响规律。实验结果表明,温度是影响加氢反应的主要因素,在催化剂用量为5%(与苊重量比)、压力2.0 MPa、反应15 h条件下,当反应温度为140℃,主要生成四氢苊产品,选择性为94%,反应温度为180℃,主要生成全氢苊产品,选择性为98%。     

用GC/MS研究含α-活泼氢芳烃与硝基苯的反应

在常温常压下，研究了苊、蒽、萘、芴、1-甲基萘（1-MN）、2,6-二甲基萘（2,6-DMN）、苯酚、α-萘酚与PhNO2(硝基苯)在Lewis酸AlCl3催化作用下的反应。结果发现，蒽、萘和苯酚与PhNO2不反应，苊、芴、1-MN、2,6-DMN和α-萘酚与PhNO2都能反应生成相应的苯胺基芳烃。GC/MS分析表明反应活性顺序为苊＞1-MN＞2,6-DMN＞芴，根据超共轭效应可以合理解释含α-活泼氢芳烃反应活性顺序。控制AlCl3与苊的摩尔比值为1.2和2.4左右，重结晶苊与PhNO2的反应产物分别得到联苊和5-苯胺基苊纯品，利用GC、GC/MS、FTIR和UV等分析测试手段对其进行了结构鉴定。     

含α-活泼氢芳烃与硝基苯的反应及其机理研究

研究了常温常压下某些芳烃与硝基苯在Lewis酸AlCl3催化作用下的反应,发现含α-活泼氢的芳烃能与硝基苯(PhNO2)反应生成相应的N-苯基芳胺。苊、芴、1-甲基萘(1-MN)、2,6-二甲基萘(2,6-DMN)与PhNO2反应的活性顺序为苊>1-MN>2,6-DMN>芴。由苊与PhNO2的反应,在控制AlCl3与苊的摩尔比为1·2和2·4左右时,重结晶反应产物可得到联苊和5-(N-苯基)氨基苊。根据实验结果,提出苊与PhNO2在AlCl3作用下的反应符合氢阳离子自由基的亲电加成-自由基亲电取代-自由基亲核加成历程。     

5-硝基二氢苊在无显影气相光刻中的光致诱蚀作用的研究——5-硝基二氢苊的光氧化反应

5-硝基二氢苊的光氧化作用在无显影气相光刻中起着重要作用。我们通过红外,核磁共振、色质联用等手段对其光氧化产物进行了分析,并合成了有关化合物进行对照,确认5-硝基二氢苊的主要光氧化产物是5-硝基苊、5-硝基二氢苊酮、羟基-5-硝基二氢苊。     

三分子激基复合物的研究

本文证实了苊与1,4-二氰基苯(DCB)可以形成激基复合物,同时当苊的浓度较大时,也可以生成三分子的激基复合物。此外还证明了聚苊可以生成非相邻的激基缔合物,聚苊与DCB也可以生成三分子激基复合物。通过光物理过程的动力学推导,证明在聚苊体系中,先生成(DA)^*,然后再形成(DDA)^*三分子激基复合物。     

痕量芴、苊、蒽和(艹北)的同时偏振-同步荧光分析

本文建立了痕量芴、苊、蒽和(艹北)的同时偏振-同步荧光分析法.该法能有效地抑制同步扫描过程中散射光的影响,从而提高测定的灵敏度.芴、苊、蒽和(艹北)的检测限分别为(ng/mL):1.1、10.0、1.8、0.26,相对标准偏差不大于4.2％.     

聚乙二醇相转移催化合成苊酮

研究了在铬酸酐、冰醋酸和相转移催化剂聚乙二醇存在下苊的氧化反应，较温和的条件可高产率地得到苊酮。     

高效液相色谱分离偏振同步荧光同时检测环境样品中的茐、苊、 、苯并[a]荧蒽

以高效液相色谱（ＨＰＬＣ）为分离手段，偏振同步荧光法为检测手段，实现了环境样 品中茐、苊、　、苯并[a]荧蒽（Ｂ［ａ］Ａ）的同时检测。所建方法对茐、苊、　、Ｂ[a]Ａ的检测限分 别为 ０．０３９，０．０４６，０．０１６和 ０．０４２（ｍｇ／Ｌ）。该法用于大气、海洋沉积物中的茐、苊、　、Ｂ[a] Ａ的同时测定，结果满意。     

η6-苊烯三羰基铬配合物的合成、结构及光谱性质研究

采用苊烯配体与三胺基三羰基铬在四氢呋喃中回流反应,合成了η6-苊烯三羰基铬配合物.通过元素分析、IR、1HNMR、13CNMR、MS和X射线单晶衍射对其结构进行了表征,比较了标题配合物与其自由配体的光物理行为.晶体结构分析表明,标题配合物属单斜晶系,空间群P21/c,Z=4,a=0.8719(7)nm,b=1.2436(10)nm,c=1.1504(9)nm,β=111.835(13)°,Cr(CO)3基团可与苊烯配体中的2个苯环中的任意一个配位,形成2个异构体(R,S),并以1:1的比例在其晶胞单元中反向面对面堆积,这种异构体共存于晶体中归属于Cr(CO)3基团在配体芳环之间的配位移动重排(IRHRs).     

反应温度对煤液化中油用镍钼催化剂加氢产物组成和性质的影响

用商业镍钼催化剂对Wandoan 煤加氢液化中油进行加氢精制,研究产物油性质和反应温度的关系。实验在氢气压力为10MPa、温度范围为310—390℃、体积空速为1h~(-1)的条件下进行。用气相色谱和色谱-质潜联用仪分析产物油,发现其中主要含有环己烷、苯的衍生物、吲哚、四氢萘、萘、联苯、苊、二苯并呋喃、芴和菲及它们的烷基取代物和加氢衍生物。     

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.     

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%).     

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.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

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.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.