亲电硫试剂参与的2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮的合成

以(E)-1-(2-对甲苯磺酰胺基)-3-芳基丙-2-烯-1-酮(1)为底物与N-硫代丁二酰亚胺(2)通过亲电环化反应合成了2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮类化合物。以三氟化硼乙醚(20(mol)%)为催化剂、1,2-二氯乙烷为溶剂、60℃下反应,可以60%～92%的收率得到一系列2-芳基-3-硫代-4(1H)-喹啉酮衍生物。化合物3a～3l未见文献报道,其结构均经1H NMR、13C NMR以及高分辨质谱进行确定。     

TMSCl促进的分子内亲核取代反应合成α-亚烷基-哌啶酮

以烯基碘代物为底物,丁基锂为锂代试剂,THF为溶剂,在TMSCl促进下通过分子内亲核取代反应合成了4个α-亚烷基-哌啶酮(2a~2d),其结构经~1H NMR,~(13)C NMR和HR-MS(ESI)确证。在最优反应条件(1 2 mmol,n-Bu Li 2.4 mmol,TMSCl 3 mmol,THF 20 m L,于170℃反应1 h)下,2a~2d收率68%~84%。     

碘催化烯烃双官能团化反应制备β-羟基硫醚

室温下,以碘单质为催化剂,以空气为氧化剂,以乙腈水溶液为反应溶剂, 烯烃和硫代磺酸酯反应生成β-羟基硫醚化合物3a~3x（3i, 3k, 3r, 3s为新化合物）,采用¹H NMR,¹³C NMR,MS(ESI)和元素分析对其结构进行确证。以S-(4-氯苯基)-4-氯硫代苯磺酸酯(1)和苯乙烯(2)的反应为模板,对反应条件进行优化。结果表明：最佳反应条件为：S-(4-氯苯基)-4-氯硫代苯磺酸酯 0.5 mmol,苯乙烯1 mmol,催化剂碘用量为0.1 mmol,乙腈1.5 mL,去离子水0.5 mL,室温下反应2 h,收率可达82%。     

亲电硫试剂参与的2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮的合成研究

本文报道了以(E)-1-(2-对甲苯磺酰胺基)-3-芳基丙-2-烯-1-酮(1)为底物与N-硫代丁二酰亚胺(2)通过亲电环化反应合成2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮类化合物。以三氟化硼乙醚为催化剂(20 mol %),1,2-二氯乙烷为溶剂,反应温度为60 _oC,可以60-92%的收率得到一系列2-芳基-3-硫代-4(1H)-喹啉酮衍生物,化合物3a-k均未见文献报道,其结构均经过₁H NMR, ₁₃C NMR以及高分辨质谱进行确定。     

3-碘-5-甲基-1,5-苯并硫氮杂(艹卓)-4(5H)-酮的合成

以2-甲基硫代苯胺为原料,通过酰化反应、碘环化反应合成了3-碘-5-甲基-1,5-苯并硫氮杂(艹卓)-4(5H)-酮,总收率86.3%,其结构经NMR,IR和MS表征.     

3,3-二取代3-吲哚-3'-基氧化吲哚的立体选择性合成

以10 mol%(R,R)-环己二胺衍生的手性双功能硫脲叔胺(4b)为催化剂,3'-吲哚-3-氧化吲哚与α-氨基砜为原料,经3'-吲哚-3-氧化吲哚与原位生成的N-Boc芳香醛亚胺的不对称Mannich反应,合成了20个3,3-二取代3-吲哚-3'-基氧化吲哚类化合物(3a~3t),分离收率54%~98%,dr值90∶10~99∶1,其结构经~1H NMR,~(13)C NMR和HR-MS(ESI-TOF)表征。     

取代呋喃的合成新方法

本文提供了一种合成2-取代呋喃和2,5-二取代呋喃的方法,即通过碘代烃与末端炔丁醇发生Sonogashira偶联反应,生成3-炔-1-醇,再在Dess-Martin Periodinane的作用下发生异构环化得到一系列2-取代呋喃和2,5-二取代呋喃类化合物。通过该方法得到4种目标物,其结构经~1H NMR、~(13)C NMR和HRMS得到确证。     

一种二苯乙烯羟胺类化合物的合成及其在糖类检测中的应用研究

以4-溴苯丙醇为初始原料,与苯乙烯经Heck反应得化合物2a;化合物2a在邻碘酰基苯甲酸的氧化作用下生成化合物3a;化合物3a在酸性条件下进行肟化反应得化合物4a;化合物4a在酸性条件下被氰基硼氢化钠还原,合成了一种二苯乙烯类羟胺化合物(5a, 20.0%),其结构经~1H NMR,~(13)C NMR, IR和LC-MS(ESI)表征。化合物5a的光学性质研究结果表明:激发波长为312 nm,发射波长为357 nm,斯托克斯位移为45 nm,荧光量子产率为0.11。以类似方法合成了氘代标记的化合物5b,化合物5a和5b能在温和条件下与聚糖类物质快速发生衍生化反应,得到高强度质谱信号的衍生产物。通过比较"轻"、"重"同位素标记的聚糖衍生物相应的质谱峰强度,可以获得具有相同化学特征的聚糖的相对含量,实现聚糖的定量分析。     

3-碘-5-甲基-1,5-苯并硫氮杂-4(5H)-酮的合成

以2-甲基硫代苯胺为原料,通过酰化反应、碘环化反应合成了3-碘-5-甲基-1,5-苯并硫氮杂-4(5H)-酮,总收率86.3%,其结构经NMR,IR和MS表征。     

硫代靛红衍生的三氟乙基酮亚胺的合成

以硫代靛红和三氟乙胺盐酸盐为原料,以原甲酸三甲酯为脱水剂,在温和条件下以5%～35%收率合成了11个新型的硫代靛红衍生的三氟乙基酮亚胺衍生物3a～3k,其结构经¹H NMR、¹³C NMR和HR-MS(ESI-TOF)表征。初步尝试了该亚胺和苯并噻吩砜的[3+2]环加成反应,得到了含三氟甲基的多环杂环化合物。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

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%).     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.