卓酚酮基础的查尔酮衍生物(E)-5-溴-3-(3-芳基丙烯酰基)卓酚酮的合成(英文)

3-乙酰基-5-溴-卓酚酮与不同取代的苯甲醛类化合物通过Claisen-Schmidt缩合反应合成一系列结构新颖的卓酚酮取代的查尔酮类衍生物。该方法使用5%KOH溶液作为催化剂,50%甲醇水溶液作为溶剂,具有操作简便、反应条件温和、收率高等优点。所合成标题化合物的结构经IR、1H NMR、MS和元素分析得以证实。     

3-取代卓酚酮5位偶联产物的溴氧化成环反应

报道了采用溴氧化3-异丙烯基卓酚酮和3-肉桂酰基卓酚酮合成杂环并卓酮化合物的新方法。3-异丙烯基卓酚酮5位偶联产物1a-1f和3-肉桂酰基卓酚酮5位偶联产物3a-3d分别在吡啶介质中与过量溴作用生成5-取代苯偶氮基-7-溴-3-甲基-8-氢环庚并呋喃-8-酮2a-2f和6-取代苯偶氮基-2-苯基-8-溴-4,9-二氢环庚并吡喃-4,9-二酮4a-4d。     

查尔酮衍生物E-2-(甲氨基)-7-(3-(吡啶基)丙烯酰基)卓酮的合成

以2-乙酰基-7-(甲氨基)卓酮(1)为原料,经由与各种吡啶醛的Claisen-Schmidt缩合反应得到查尔酮衍生物E-2-(甲氨基)-7-(3-(吡啶基)丙烯酰基)卓酮(2～5).全部合成产物均为新化合物,未见文献报道;其结构均由红外光谱分析、1H核磁共振、质谱及元素分析得以证实.     

双查尔酮衍生物的合成和三阶非线性光学性质

合成一种新颖的D-π-A-π-D型双查尔酮衍生物4,4?-二[3-(芘-1-基)丙烯酰基]联苯,经IR、1H NMR、MS和元素分析对其结构进行表征.在波长为480 nm、脉宽为4 ns的激光脉冲激发下,应用4f相位相干成像技术测量了其三阶光学非线性性质,并测定了紫外光谱和DSC曲线.     

含卓酚酮基团的四乙酰基半乳糖苷的合成

环庚三烯酚酮;含卓酚酮基团的四乙酰基半乳糖苷的合成;Koenigs-Knorr糖基化反应     

羟基查尔酮类衍生物的合成

4-羟基苯乙酮或2,4-二羟基苯乙酮与取代苯甲醛在乙二醇溶液中,以硼酸为催化剂,于110～120℃反应6 h,再经柱分离精制得羟基查尔酮衍生物.产物经红外光谱、核磁共振谱、质谱确认结构.此法合成虽然收率不太高,但利用此法可更简便地一步合成出羟基查尔酮类衍生物.     

3,3'-二氨基查尔酮的合成

3;3'-二氨基查尔酮的合成;光敏性二胺;查尔酮;聚酰亚胺;合成     

SOCl2/EtOH催化查尔酮的合成

查尔酮类化合物具有多种药理作用和生物活性,同时它也是一种新型的有机非线性光学材料。经典的合成方法是使用强碱或者强酸催化苯乙酮和苯甲醛的羟醛缩合,但是副反应较多,产率偏低。近期也有文献报道使用有机碲氧化物和KF-Al2O3等试剂或者使用超声波、固相合成和微波等方法合成查尔酮。本文使用     

新型紫罗兰酮基双查尔酮缩氨基硫脲的合成及抗肿瘤活性

根据活性亚结构拼接原理,通过紫罗兰酮与(取代)苯甲醛反应合成了紫罗兰酮基双查尔酮,然后经与氨基硫脲缩合得到一系列未见报道的新型含紫罗兰酮、查尔酮及氨基硫脲3种优势结构单元的杂化体,它们的化学结构经傅里叶变换红外光谱(FT-IR)、核磁共振波谱(~1H NMR、~(13)C NMR)、元素分析及质谱(MS)等测试技术所证实。采用溴化噻唑蓝四氮唑(MTT)法初步测定其体外抗肿瘤活性(乳腺癌细胞(MCF-7),肝癌细胞(Hep G2),肺癌细胞(A549)),结果表明,对于不同类型的肿瘤细胞,化合物展现较好的增殖抑制活性。尤其是化合物3a与3b对MCF-7细胞展现较强的抗增殖活性,半数致死量(IC_(50))值分别为10.83和7.62μmol/L,化合物3e对A549细胞显示一定的增殖抑制活性效果(IC_(50)值为13.36μmol/L),化合物3f对Hep G2细胞表现了高效的抗增殖活性(IC_(50)值为8.55μmol/L)。目标物的抗增殖活性与紫罗兰酮结构及查尔酮环上不同电子效应的取代基有关。     

D-π-A-π-D型双查尔酮衍生物的合成和三阶非线性光学性质

合成一种新颖的D-π-A-π-D型双查尔酮衍生物2,6-二[3-(4-甲氧基苯基)]丙烯酰基吡啶,经IR,~1H NMR和HR-MS对其结构进行表征,采用4f相位相干成像技术测定了它的三阶NLO性质并确定了相关参数:脉宽4ns,激光波长450nm,非线性吸收系数β=0.9×10~(-9) m/W,非线性折射率n_2=-0.42×10~(-16) m~2/W,三阶非线性极化率χ~((3))=4.10×10~(-19) m~2/V~2;并测定了紫外光谱和DSC曲线.     

Bromination of norbornene derivatives: synthesis of brominated norbornanes and norbornenes

The low and high temperature bromination of 7-bromobicyclo[2.2.1]hept-2-ene and 2,7-dibromobicyclo[2.2.1]hept-2-ene were studied and the possible role of a neighboring group participation in rearrangements was investigated. The formation mechanism of the isomers as well as the role of the substituent on the rearrangement were discussed. The structure elucidation of the formed compounds was achieved by NMR spectral data; particularly, the γ-gauche effect was discussed in connection with the configuration of the bromine atoms.     

Concise synthesis of several oligostilbenes from the enzyme-promoted oxidation of brominated resveratrol

The simple synthesis of (±)-parthenostilbenins A and B and (±)-quadrangularins A and B, as well as several unnatural resveratrol dimers, was successfully accomplished for the first time. Moreover, (±)-restrytisols B, (±)-leachianols F and G were efficiently prepared with higher yields compared with those in the literatures. The regioselective oxidative coupling reactions of 3,5-dibromo-resveratrol catalyzed by different enzymes in various solvent systems were used as key steps. The coupling mechanisms for the formation of distinct dimeric skeletons were also proposed.     

Studies directed toward total synthesis of rhodocomatulins: A regioselective synthesis of brominated hydroxyanthraquinones by anionic annulations

In this work, brominated hydroxyanthraquinones, which are the core structural motif of naturally occurring bromorhodocomatulins, were successfully synthesized using Hauser annulation reaction as the key step. When brominated Michael acceptors (brominated p-quinone monoketals) and cyanophthalides or bromocyanophthalides (Hauser donors) were reacted under the annulation conditions, brominated anthraquinones were obtained with 81–87% yields for four examples. On acidic quenching, products were obtained as solid which were separated by filtration and purified by recrystallization in acetone. No chromatography was required.     

Bromination of quinoxaline and derivatives: Effective synthesis of some new brominated quinoxalines

The synthesis of brominated quinoxaline derivatives starting from several kinds of quinoxaline by different bromination strategies was studied. First the synthesis of some brominated quinoxalines was accomplished along with the development of an alternative and effective synthesis of some known compounds. A new, clean, and effective synthetic method for selective reduction of quinoxaline to 1,2,3,4-tetrahydroquinoxaline was also developed. The products obtained were characterized by means of NMR spectroscopy, elemental analyses, and mass spectrometry.     

An efficient synthesis of brominated 4-alkyl-2(5H)-furanones

A versatile method for the synthesis of novel brominated 4-alkyl-2(5H)-furanones under mild reaction conditions is described. This synthetic strategy requires only one chromatographic separation over six steps and employs the cyclodehydration of brominated levulinic acid as the key transformation.     

Efficient synthesis of brominated tetrathiafulvalene (TTF) derivatives: solid-state structure and electrochemical behaviour

An efficient synthesis is reported for 4,5-dibromo-[1,3]dithiole-2-thione (1) and 4-bromo-1,3-dithiole-2-thione (7) by bromination of lithiated vinylene trithiocarbonate. Compound 1 acts as a convenient precursor to a number of asymmetric electron donors. This is exemplified by the formation of 4,5-dibromo-4′,5′-bis(2′-cyanoethylsulfanyl)TTF (3) by cross-coupling methodology and subsequent conversion into 4,5-dibromo-4′,5′-ethylenedithioTTF (4) by reaction with caesium hydroxide and 1,2-dibromoethane. The new donor 4,5-dibromo-4′,5′-ethylenedithiodiselenadithiafulvalene (5) was prepared by cross-coupling of 1 and 4,5-ethylenedithio-1,3-diselenol-2-one (6). The X-ray structures of 3 and 5 are reported.     

Efficient total synthesis of bastadin 6, an anti-angiogenic brominated tyrosine-derived metabolite from marine sponge

An efficient total synthesis of bastadin 6 (1), a cyclic tetramer of brominated tyrosine derivatives from the marine sponge, Ianthella basta, with selective anti-angiogenic activity, was accomplished. We developed a novel Ce(IV)-mediated oxidative coupling reaction of 2,6-dibromophenols to give the diaryl ether derivatives, the characteristic segment of 1. Condensation of two segments and subsequent intramolecular macrocyclization gave bastadin 6 (1) in nine steps, 26% overall yield.     

Recent developments in the analysis of brominated flame retardants and brominated natural compounds

This article reviews recent literature on the analysis of brominated flame retardants (BFRs) and brominated natural compounds (BNCs). The main literature sources are reviews from the last five years and research articles reporting new analytical developments published between 2003 and 2006. Sample pretreatment, extraction, clean-up and fractionation, injection techniques, chromatographic separation, detection methods, quality control and method validation are discussed. Only few new techniques, such as solid-phase microextraction (SPME) or pressurized liquid extraction (PLE), have been investigated for their ability of combining the extraction and clean-up steps. With respect to the separation of BFRs, the most important developments were the use of comprehensive two-dimensional gas chromatography for polybrominated diphenyl ethers (PBDEs) and the growing tendency for liquid-chromatographic techniques for hexabromocyclododecane (HBCD) stereoisomers and of tetrabromobisphenol-A (TBBP-A). At the detection stage, mass spectrometry (MS) has been developed as well-established and reliable technology in the identification and quantification of BFRs. A growing attention has been paid to quality assurance. Interlaboratory exercises directed towards BFRs have grown in popularity and have enabled laboratories to validate analytical methods and to guarantee the quality of their results. The analytical procedures used for the identification and characterization of several classes of BNCs, such as methoxylated polybrominated diphenyl ethers (MeO-PBDEs) (also metabolites of PBDEs), halogenated methyl or dimethyl bipyrroles (DBPs), are reviewed here for the first time. These compounds were generally identified during the routine analysis of BFRs and have received little attention until recently. For each topic, an overview is presented of its current status.     

Detoxification of brominated pyrolysis oils

The development of an innovative technology for the pyrolytic conversion of brominated phenols in a reductive medium aimed at product recovery for commercial use is discussed in this paper. Brominated phenols are toxic products, which contaminate pyrolysis oil of wastes from electronic and electrical equipment (WEEE). The pyrolysis experiments were carried out with 2,6-dibromophenol, tetrabromobisphenol A, WEEE pyrolysis oil and polypropylene or polyethylene in encapsulated ampoules under inert atmosphere in quasi-isothermal conditions (300–400 °C) with a different residence time (10–30 min). Optimal conditions were found to be the use of polypropylene at 350 °C with a residence time of 20 min. The main pyrolysis products were identified as HBr and phenol. A radical debromination mechanism for the pyrolytic destruction of brominated phenols is suggested.