One-pot Synthesis of α,β-Dehydroamino Derivatives from β,β-Dicyanostyrene with 1,3-Dibromo-5,5-dimethylhydantoin Promoted by Mild Base

The reaction of β,β-dicyanostyrene derivatives(1) with 1,3-dibromo-5,5-dimethylhydantoin(DBDMH) was systematicly studied. The reaction could generate different products when promoted by different mild bases. When the reaction was promoted by NaOAc(100%, molar ratio to compound 1), β,β-dicyanostyrene derivatives could be directly converted into corresponding α,β-dehydroamino derivatives in good to excellent yields in one-pot. When the reaction was promoted by K₃PO₄(80%, molar ratio to compound 1), the corresponding α,β-dehydroamino and double-α,β-dehydroamino compounds were simultaneously obtained and the total conversion of β,β-dicyanostyrene derivatives was up to 90% or higher.     

K3PO4-Catalyzed Regiospecific Bromoamidation of β, β-Dicyanostyrene Derivatives with N-Bromoacetamide（NBA）

An efficient method for the bromoamidation of β,β-dicyanostyrene derivatives with N-bromoacetamide （NBA） was developed.This protocol provides a convenient process to convert β,β-dicyanostyrene derivatives into the vicinal haloamines in excellent yields（up to 99％） at room temperature in the presence of anhydrous K3PO4 as a catalyst without the protection of the inert gaseous in CH2Cl2.A total of 11 examples were investigated and all the products showed the regionspecific feature.Based on the observation of different activities for the different substrates involving the electron-rich or electron-deficient β,β-dicyanostyrenes,a possible Michael addition mechanism was proposed.     

Stereoselective Synthesis of Sulfonyl-substituted trans-2,3-Dihydrofuran Derivatives via Reaction of Arsonium Ylides with α,β-Unsaturated Ketones

Trans-2,3-dihydrofuran derivatives 3 or 4 substituted with a sulfonyl group were prepared with high chemoselectivity and good yields by [1＋4]-addition reaction of α,β-unsaturated ketones 1 with arsonium bromide 2 in CH2Cl2 in the presence of potassium carbonate at room temperature.The structures of the products were characterized by IR,MS,^1H NMR,elemental analysis and single crystal X-ray diffraction analysis.A mechanism for the formation of products was also proposed.     

含磺胺嘧啶结构单元β-氨基酮的合成及其生物活性

通过原子经济的Mannich反应实现了磺胺嘧啶、1-萘乙酮与芳香醛三组分的连接,直接合成了16个含有磺胺嘧啶结构单元的未见报道的β-氨基酮;所得化合物经¹H NMR、¹³C NMR、HRMS和MS等技术手段确证其结构。 生物活性测试结果显示,在17.04~19.69 nmol/L浓度范围内,所有目标分子的α-葡萄糖苷酶抑制活性很弱,但部分目标分子的过氧化物酶体增殖物激活受体反应元件(PPRE)激动活性较好,最高达到了52%。     

β-环糊精及衍生物与β-胡萝卜素包合物性质

为了改善β-胡萝卜素的理化性质,如水溶性和光稳定性等,分别制备了β-胡萝卜素与β-环糊精、2-羟丙基-β-环糊精、磺丁基醚-β-环糊精的固体包合物。利用紫外-可见吸收光谱、傅里叶红外转换光谱和核磁技术对β-胡萝卜素与环糊精及其衍生物的包合物进行研究。通过对包合物理化性质的研究发现:通过β-环糊精、2-羟丙基-β-环糊精、磺丁基醚-β-环糊精包合后的β-胡萝卜素的理化性质,包括热稳定性、光稳定性和抗氧化性,均有显著提高;经2-羟丙基-β-环糊精和磺丁基醚-β-环糊精包合后,β-胡萝卜素分别增溶12倍和18倍。     

超支化聚乙烯亚胺-聚天冬氨酸苄酯共聚物的制备及性能

以超支化聚合物聚乙烯亚胺为引发剂, 天冬氨酸苄酯-NCA为单体, 利用热开环聚合法合成了超支化聚乙烯亚胺-聚天冬氨酸苄酯共聚物(PEI-PBLA). 用核磁共振波谱对PEI-PBLA的化学结构进行了表征. 研究了PEI-PBLA在水溶液及有机溶液中的自组装行为. 以芘为荧光探针测定了共聚物在水中形成胶束的临界胶束浓度. 以甲基橙为客体分子, 研究了共聚物胶束的包覆能力, 结果表明, 共聚物对客体分子的吸附与溶液的pH值有关. 研究了共聚物与质粒DNA的复合发现, PEI-PBLA能够很好地与质粒DNA复合, 并且可以避免DNA酶的降解, 对其起到一定的保护作用. 此聚合物在药物传输、可控释放及基因载体等方面都有着潜在的应用价值.     

水相介质中碳酸钾/硫脲联合促进邻位氨基溴转变成α,β-脱氢氨的研究

建立了在水相介质中, 在碳酸钾/硫脲联合促进下, 具有邻位氨基溴的酯和邻位氨基溴的酮在室温下发生溴化氢消除反应, 高收率地制备α,β-脱氢氨(功能化烯胺)的新方法. 共考察了23种不同结构α,β-邻位氨基溴的酯和α,β-邻位氨基溴的酮的反应情况, 证明该方法具有广泛的适应性. 实验发现, 无论底物为α-氨基-β-溴结构还是α-溴-β-氨基结构, 反应过程中都要经过一个氮丙啶过程, 而氮丙啶的开环是区域专一的, 因此产物具有区域专一性(烯键上的氨基均处在羰基的α-位). 所有产物的结构均经过核磁共振波谱及高分辩率质谱确证. 克量级放大实验结果表明, 该方法具有一定的用于工业化生产的可行性.     

Enantioselective trapping of oxonium ylide intermediates by N-benzhydryl-α-imino ester:Synthesis of β-tetrasubstituted α-amino acids

A synergistic rhodium(Ⅱ)/phosphoric acid catalyzed three component reaction of 3-diazooxindoles,alcohols and N-benzhydryl-α-imino ester is developed for the efficient construction of chiral β-alkoxy C~β-tetrasubstituted α-amino acid derivatives in good yields and with excellent diastereoselectivities and high enantioselectivities.The synthetic application of the resulting products was illustrated by reducing with Pd/C under H_2 atmosphere followed reacting with CSCl_2 at room temperature to rapid afford 3-spirocyclic oxindole in a good yield with a chirality retainment.The three-component reaction is proposed to proceed through an electrophilic trapping of the oxonium ylides by N-benzhydryl-α-imino ester.     

β-萘甲酰化β-环糊精的分子识别性能研究

最近二十年,外形似“锥简”,腔内疏水,脏外亲水的环糊精（Cyclodextrin,CD包括a,o,7－CD等）,以其特有的结构在模拟酶、分子识别等众多领域内深受广大科学工作者重视［’－‘］．为了获得更有效的模拟酶及分子识别功能体,我们已合成并报道了一系列含有发色基团的CD衍生物卜一句．本文利用基紫外光谱对产一茶甲酸化公CD的分子识别性能作了研究,结果显示3一位修饰CD（3一氧一八茶甲酸基一只CD）1对客体（环己醇）的包结性能是6一位修饰CD（6一氧一界禁甲酸基一八CD）2的4．4倍·结果还显示用环乙烷作客体时与主体正的包结和用…     

Functional β-Cyclodextrin Coating by Electrodeposition on Stainless Steel for Drug Loading and Release

β-Cyclodextrin(β-CD) can be used for drug loading and release in biomedical application. β-Cyclodextrinsalicylate(β-CD-S) was synthesized by transesterification and then was electrodeposited on the surface of stainless steel(SS) by the anodic electrooxidation polymerization of the salicylate. ¹H NMR spectrometry was used to determine the structure of β-CD-S. FTIR spectroscopy and XPS were applied to verifying the synthesized β-CD-S and the existence of the electrodeposited layer on the SS surface, respectively. Tafel plots and electrochemical impedance spectroscopy(EIS) technologies were used to estimate the corrosion resistance of β-CD-covered stainless steel. Electrochemical quartz crystal microbalance was applied to determining the drug loading of the stainless steel before and after its modification. E. coli was selected as a harmful microbe to evaluate the antibacterial properties of the stainless steel with the comparison of optical density values.     

新型2,4-二取代四氢吡咯-3-羧酸衍生物的合成

N-三甲硅甲基苯甲醛亚胺为非稳定型亚甲胺基叶立德前体,在磷酸催化下与取代噁唑烷酮烯烃经1,3-偶极环加成反应合成了10个具有cis-trans立体结构的新型2,3,4-三取代四氢吡咯-3-羧酸衍生物（3a~3j）,收率65%~75%,其结构经¹H NMR, ¹³C NMR和HR-MS表征。3b的立体结构经X-单晶衍射确证。     

Synthesis of β-Pinene/THF Block Copolymers

The living cationic polymerization of β-pinene was carried out with α-chloroethylbenzene(PEC)/TiCl₄/Ti(OiPr)₄ initiating system in CH₂C1₂ at -40℃. After 25 min of reaction(β-pinene conversion~100%),the resulted living poly(β-pinene) was capped with a few units of styrene and then the polymerization was quenched to give β-pinene macroinitiator with benzenyl chloride chain end (P(β-p)-St-Cl). The structure of the macroinitiator was confirmed by ¹H NMR (Fig.l). The macroinitiator, in conjunction with AgSbF₆ or AgC1O₄,was used to initiate the ring-opening cationic polymerization of THF in the presence of propylene oxide promoter. GPC analysis of the obtained polymers showed that AgSbF₆ system led to almost pure block copolymers of β-pinene with THF, whereas AgC1O₄ system gave mixtures of block copolymers and low molecular weight homopolymers of THF and unreacted macroinitiator (Fig.2). ¹H NMR analysis further confirmed the formation of β-pinene/THF block copolymers with macroinitiaor/AgSbF₆ system (Fig.3).     

硅胶支载稀土氯化钐一步催化合成多取代Mannich碱

采用硅胶与稀土氯化钐在甲苯或四氯化碳中反应,制备了硅胶支载稀土氯化钐. 与已报道的支载型催化剂相比,所制备的硅胶支载稀土氯化钐作为催化剂具有支载量稳定、催化反应时间短、产率高和选择性强等优点,同时催化反应条件温和、操作简便、不污染环境且催化剂重复利用率高. 室温条件下,以硅胶支载稀土氯化钐作为催化剂催化对甲氧基苯乙酮、芳香醛和芳香胺的三组分体系,利用“一锅法”合成了28种新的β-氨基酮类化合物,并探索了不同反应条件对产率的影响. 催化剂经过IR和XRD表征,催化反应产物通过IR、¹H NMR和元素分析确定.     

Triplet excitation dynamics of β-carotene studied in three solvents by ns flash photolysis spectroscopy

Upon anthracene-sensitizing, triplet excitation dynamics of β-carotene(β-Car) were studied in nhexane, in methanol, and in acetonitrile, respectively, by ns flash photolysis spectroscopy. In n-hexane,only the bleaching of the ground state absorption(GSB) and the excitation triplet(~3Car*) absorption were observed, and there were no cationic species detected. In both methanol and acetonitrile, similar excitation dynamics were observed, i.e.,~3Car* having a similar lifetime to that in n-hexane, and the immediate generation of the cation dehydrodimer(~#[Car]2~+) upon excitation following transformation into the radical cation Car*~+, since Car*~+ has much longer lifetime in acetonitrile than in methanol. The results prove that both solvent and carotenoid structure determine the triplet excitation mechanism.     

Design,Synthesis and Biological Evaluation of Sulfenimine Cephalosporin Analogues as β-Lactamase Inhibitors

A series of sulfenimine cephalosporin derivatives(6a-6t) was designed, synthesized and evaluated for their inhibitory activity against class A β-lactamase(TEM-1) derived from E. coli, and class C β-lactamase (cephalosporinase) derived from wild Bacillus subtilis in cell-free systems. Most of the tested compounds showed enhanced inhibitory activity against class C β-lactamase(cephalosporinase) compared with tazobactam. The most promising compounds 6c and 6o in combination with cefradine(IC₅₀=1.80 and 1.59 μmol/L, respectively) were further investigated against a series of clinical isolated β-lactamase-producing bacterial strains. The results reveal that compounds 6c and 6o in combination with cefradine show two to four times more activity than cefradine alone against methicillin-sensitive Staphylococcus aureus(MSSA) and Klebsiella pneumoniae. The data suggest that the sulfenimine moiety may be beneficial to the activity and selectivity of inhibitors.     

β-硝基苯乙烯衍生物与二溴海因高度区域选择性氨溴加成反应

以β-硝基苯乙烯衍生物为底物, 二溴海因为氮源/卤素源, 乙腈作溶剂, 建立了碳碳双键上高度区域选择性氨溴加成反应新体系. β-硝基苯乙烯衍生物与二溴海因在室温无水碳酸钠催化下反应, 可高收率获得邻位氨溴加成产物, 最高收率达97%; β-甲基-β-硝基苯乙烯衍生物在氢氧化钾催化下回流反应, 也可高收率得到邻位氨溴加成产物, 最高收率达95%. 实验结果表明, 对于硝基苯乙烯衍生物, 当苯环4-位具有强供电子基团如CH₃O时, 可以得到单一的α-氨基-β-溴加成产物, 但其收率相对较低; 当硝基苯乙烯衍生物的苯环4-位有强吸电子基团如NO₂时, 反应收率则很高. 这一实验结果证明β-硝基苯乙烯衍生物(缺电子烯烃)与二溴海因的氨溴加成反应具有亲核加成的特征. 本文共考察了20种不同结构的β-硝基苯乙烯衍生物的氨溴加成反应情况, 其产物结构经核磁共振波谱及质谱分析确证, 并提出了可能的反应机理.     

1,2,3-三取代贫电子环丙烷衍生物与甲醇反应的研究

环丙基的化学性质类似于烯键,亲电试剂对环丙基的反应已研究得较多［１－４］．由于带多个吸电子官能基的环丙烷衍生物的合成较为困难,因此,有关亲核试剂对环丙基的反应报道较少．作者通过肿叶立德 １与米氏酸衍生物 ２的反应,简便地合成了一系列 １,２,３一三取代贫电子环丙烷衍生物３［５,６］．并用此方法高立体选择性地合成了一系列二氢呋喃衍生物［７］及γ－丁酸内酯衍生物［８］等．为弄清亲核试剂对贫电子环丙烷衍生物的反应情况,作者对亲核试剂与环丙烷类衍生物化合物３的反应作了研究．本文报道顺－１－苯甲酰基－２－对…     

K3PO4-promoted Cyclopropanation of Electron-deficient Alkenes with 2-Bromo-1,3-propanedione Compounds

An easy and efficient method for the synthesis of multisubstituted cyclopropane derivatives from electron-deficicent alkenes with 2-bromo-1,3-propanedione compounds was described. For this method, ethyl α-cyanocinnamate derivatives 1 and β,β-dicyanostyrene derivatives 4 can all smoothly react with 2-bromo-1,3-propanedione compounds 2 to afford the corresponding multisubstituted cyclopropane derivatives 3 and 5 in good to excellent yields(up to 100%) promoted by anhydrous K₃PO₄ in DMF at room temperature, respectively. A possible mechanism of this reaction was proposed. Structures of all the products were confirmed by ¹H NMR, ¹³C NMR and HRMS.     

南蛇藤昆虫拒食倍半萜成分的研究(Ⅱ)

南蛇藤昆虫拒食倍半萜成分的研究（Ⅱ）王明安,陈馥衡（北京农业大学应用化学系,北京,１０００９４）关键词南蛇藤,倍半萜,结构分析卫矛科植物含多种类型β－二氢沉香呋喃倍半萜多醇酯衍生物和生物碱［１］,有些化合物显示了良好的昆虫拒食和抗肿瘤活性［２～４］．...     

键联环糊精、糖苷的卟啉及金属卟啉的合成

全甲基化-6-羟基-β-环糊精(PMβ-CD-CH₂OH)在N₂气流下与三氟甲基磺酸酐反应得到全甲基化-6-三氟甲基磺酸酯-β-环糊精(PMβ-CD-CH₂OTf)(6).6分别与5-(p-氨基苯基)-10,15,20-三苯基镍(钌羰基)卟啉[NiTP_NH2P](2)和[Ru(CO)TP_NH2P](3)缩合得到化合物7和8.1-溴-2,3,4,6-O-乙酰基-α-D-葡萄糖(4)和1-溴-2,3,5-O-乙酰-β-D-呋喃糖(5)分别与H₂TP_NH2P(1)反应得到化合物9和10.新化合物6-10经IR,UV-Vis,¹HNMR和元素分析确证,其中化合物6由MS谱进一步确定.