双功能偶联剂SPC的一种新合成方法及其碘标记

放射性碘标记药物广泛用于医学检验及临床诊断和治疗中。放射性碘标记蛋白质不管是采用Ch-T、Iodogen直接标记方法还是采用Bolton-Hunter试剂间接标记方法,其存在的主要问题是标记物可能在体内严重脱碘[1,2]。为了克服这一问题,人们不断改进碘标记方法。其中,Zalutsky、W ilbur     

新试剂1-偶氮苯基-3-(5-硝基-2-吡啶)-三氮烯的合成及其与镉的显色反应

三氮烯试剂是测定ⅠＢ、ⅡＢ族金属元素的优良试剂。近年来 ,对该类试剂中的取代苯重氮氨基苯的合成和分析应用报道较多[1 ,2 ] ,但对含杂环的三氮烯试剂的研究报道较少。我们曾将安替比林[3] 、苯并噻唑[4,5] 、噻唑[6] 引入该类试剂中 ,使试剂灵敏度有所提高。为进一步探讨此类试剂的分析性能 ,我们将 5 硝基吡啶引入 ,合成了 1 偶氮苯基 3 ( 5 硝基 2 吡啶 ) 三氮烯 (ＡＢＮＰＤＴ)。分子中含有杂环吡啶的同时还有强吸电子———ＮＯ2存在 ,另一端为具有长共轭链的偶氮苯基 ,这样更有利于试剂分子中电子的流动 ,从而改善分析性能。…     

新试剂HABST分光光度法测定铜

硫脲类试剂因含有Ｓ ,Ｎ配位原子而可与无机离子形成配合物 ,近年来已被用于定性分析和定量测定。对氨基苯磺酸钠类硫脲因其良好的水溶性而避免了以往测铜试剂需有机相中进行的繁琐处理。Ｎ 庚基 Ｎ′ (对氨基苯磺酸钠 )硫脲(ＨＡＢＳＴ) [1 ] 是继Ｎ 烯丙基 Ｎ′ (对氨基苯磺酸钠 )硫脲 (ＡＳＡＴＵ) [2 ] 后又合成的一种水溶性光度试剂 ,通过初步研究 ,发现它与Ａｇ+、Ｃｕ2 +有特征性反应。在此基础上 ,对其与铜的显色反应作进一步研究 ,探讨了ＨＡＢＳＴ分光光度法测定铜的最佳条件 ,在ｐＨ4.5～ 6.0的ＨＡｃ ＮａＡｃ缓冲溶液中 ,Ｃ…     

N-碘代丁二酰亚胺( NIS )制备方法的改良

N-碘代丁二酰亚胺( NIS )为一重要的有机合成试剂,作为一种温和有效的碘化剂,可碘化乙酸烯醇酯,碘化嘌呤核苷等等,也可用于分裂乙二醇类、硫缩醛或酮,尤其是它与三氟甲磺酸( TfOH )联合用作硫苷供体活化的催化剂,成为近年来应用最多效果最好的硫苷催化剂[1].     

聚苯乙烯二醋酸碘苯的合成及其在烯烃叠氮-芳硒化反应中的应用

近年来 ,高碘化合物显示出多样化的反应性能 ,广泛用于有机合成 .其中以二醋酸碘苯的应用最为广泛 [1] .Tingolio等[2 ] 报道烯烃与二醋酸碘苯、叠氮化钠及二芳基二硒化合物进行叠氮 -芳硒化反应 ,具有反应条件温和、区域选择性好等优点 ,不足之处在于副产物碘代苯不易与产物分离 ,亦不符合原子经济性原则 .合成聚合物负载的有机试剂发展极为迅速 ,其主要优点是过量的试剂 ,在反应完成后 ,通过简单过滤即可与产物分离 ,而且聚合物试剂可被再生 ,重复使用 ,充分体现了绿色化学的特征 [3 ,4 ] .为此 ,本文首先合成聚苯乙烯负载的二醋酸碘苯试…     

α-溴代二硫缩烯酮的制备及其反应

α-羰基二硫缩烯酮 ( 1 )是一类重要的有机合成中间体 ,作为 1 ,3-亲核体用于酯环、苯系芳烃及芳杂环化合物的合成[1～ 4 ] .Hosomi等 [5～ 7] 用有机铜试剂或二碘化钐和 α-羰基与二甲硫缩烯酮反应 ,将与硫相连的缩烯酮碳原子转化为亲核中心 .用不同的烷硫基作为调控基团将该类中间体用于二萜 pseu-dopterosins的合成 [8～ 10 ] ,并作为替代 Peterson法合成 1 ,1 -二烷硫基 - 1 ,3-丁二烯或 1 ,1 -二烷硫基 - 1 ,3,5 -己三烯 [11,12 ] ,从不同的角度对 α-羰基二硫缩烯酮在合成上的应用进行了新的探索 .Junjappa等 [13,14 ] 曾用 NBS和 …     

新显色剂TBDP-B-DAA与镉(Ⅱ)显色反应的研究与应用

1976年联合国粮农组织及世界卫生组织在食品污染物监测规划中 ,划定具有蓄积性毒害镉是必测项目。三氮烯类显色剂作为测定镉、汞、铜等金属离子的优良试剂 ,已广泛应用于镉、汞等元素的光度法测定。目前已合成的该类试剂大多数为取代苯基重氮氨基偶氮苯类[1～ 7] ,而双三氮烯类的报道比较少。本文首次合成了 3,3′,5 ,5′ 四溴联苯 双 (重氮氨基偶氮苯 ) (ＴＢＤＰ Ｂ ＤＡＡ) ,通过在联苯氨上引入四个溴原子 ,利用其诱导效应和ｐ孤对电子的共轭效应改善试剂的分析性能 ,同时本试剂含有两个 Ｎ =Ｎ Ｎ 功能基 ,增强了显色效果 ,与镉形成的…     

外周苯二氮受体示踪剂的合成和评价

合成了用作外周苯二氮受体潜在的选择性配体的N,N-二乙基-2-(4-碘苯基)-6-三氟甲基-咪唑并[1,2-a]吡啶-3-乙酰胺(ITFZOL). 其放射性标记物[125I]ITFZOL通过碘脱锡化反应制备, 放化得率75%~85%, 比活度大于76 GBq/μmol. 小鼠尾静脉注射[125I]ITFZIOL后, 放射性集中分布于肾上腺、肺、肾、心、嗅球和小脑等外周苯二氮受体高密度区域. 预先给与外周苯二氮受体选择性配体PK11195明显减少外周苯二氮受体高密度区域放射性分布, 提示[125I]ITFZOL对外周苯二氮受体具有较高的特异亲和性. 生物活性数据表明, [125I]ITFZO是一种潜在的选择性外周苯二氮受体单光子放射性配体.     

液相色谱-质谱对预混饲料水解液中一碘酪氨酸与二碘酪氨酸的检测

一碘酪氨酸(MIT)和二碘酪氨酸(DIT)分别是碘化酪蛋白的特征水解产物之一[1],因此,通过检测饲料水解液中的MIT和DIT可判断饲料中是否含有碘化酪蛋白.碘化酪蛋白是一种拟甲状腺激素类药物[2],具有调节动物生长发育、促进产奶、降低体脂和促进鸟类换羽[3-4]等功能.碘化酪蛋白作为饲料添加剂使用始于20世纪40年代,但随着激素类药物作为饲料添加剂在我国的全面停止使用[5],碘化酪蛋白的检测受到行业广泛关注.碘化酪蛋白为非纯物质,在饲料中的用量低,其测定存在一定困难.     

微波辐射下干反应脱肟成酮的一种新方法

肟已被广泛用于羰基化合物的表征、纯化以及酰胺的合成[1 ] 。人们可以从羰基和非羰基化合物来制备肟 (Ｂａｒｔｏｎ反应[2 ,3] )。因此 ,肟的脱肟成酮也是合成羰基化合物的一种方法。近年来 ,文献中不断有各种脱肟试剂和催化剂 ,如 :三氧化铬 硅胶[4] 、镍 (Ⅱ )复合物[5] 等的研究报道。但这些方法都是在液相中进行的 ,通常需要计量或过量的有机试剂 ,而且反应时间长、产率低[6] 。为了寻找高效的脱肟方法 ,微波辐射下的干反应脱肟研究已愈来愈引起人们的兴趣[1 ,7] ,它具有反应速度快、副反应少、产率高等优点。前文[8] 我们报道了用甲酸…     

Novel copper hydride-promoted 1,3-rearrangement of α-allenylcyclopropane systems to methylenecyclopentenes

α-Allenylcyclopropanedicarboxylates, for which a novel synthetic method has been devised by conjugate addition of a copper hydride (Stryker) reagent to α-cyclopropylpropargylic esters, have been newly found to be smoothly converted to methylenecyclopentene derivatives under mild reaction conditions by further treatment with the copper hydride reagent. The mechanistic pathway is discussed.     

The remarkable ability of lithium ion to reverse the stereoselectivity in the conjugate addition of Li[BuCuI] to a chiral N-crotonyl-2-oxazolidinone

[reaction: see text] The influence of lithium ions on the conjugate addition of the monoorganocuprate reagent, Li[BuCuI], to a chiral crotonate has been investigated. The results show that iodotrimethylsilane (TMSI) is crucial for the asymmetric conjugate addition of the copper reagent, but only in THF or when 12-crown-4 is used. The reaction is thought not to involve any halosilane in any critical steps in the organocopper mechanisms conducted in Et(2)O.     

Conjugate additions of a simple monosilylcopper reagent with use of the CuI.DMS complex: stereoselectivities and a dramatic impact by DMS

Conjugate additions utilizing the simple monosilylcuprate reagent Li[PhMe2SiCuI] to alpha,beta-unsaturated carbonyl compounds are described. The presence of dimethyl sulfide (DMS), either as a component originating from the (CuI)4(DMS)3 complex or as a solvent added, has an amazing influence on both chemical yield and the level of diastereomeric ratio (dr) of the products. Gilman-type silylcyanocuprates {Li(Ph2MeSi)2Cu/LiCN} have previously been used to guarantee good results in conjugate addition reactions. External additives such as HMPA, tributylphosphine, or dialkylzinc are not necessary in conjunction with the simple Li[PhMe2SiCuI] reagent. It is demonstrated that the monosilylcuprate reagent with DMS as the solvent is very useful with sterically hindered (beta,beta-disubstituted) enones, and provides very high yields of the beta-silylated 1,4-addition products. Since there is no oligomerization problem associated with the simple monosilylcuprate reagent, this reagent should be considered as a very useful 1,4-silyl donor to enals, enones, and enoates in conjugate addition reactions.     

Stable Pyrrole-Linked Bioconjugates through Tetrazine-Triggered Azanorbornadiene Fragmentation

An azanorbornadiene bromovinyl sulfone reagent for cysteine-selective bioconjugation has been developed. Subsequent reaction with dipyridyl tetrazine leads to bond cleavage and formation of a pyrrole-linked conjugate. The latter involves ligation of the tetrazine to the azanorbornadiene-tagged protein through inverse electron demand Diels–Alder cycloaddition with subsequent double retro-Diels–Alder reactions to form a stable pyrrole linkage. The sequence of site-selective bioconjugation followed by bioorthogonal bond cleavage was efficiently employed for the labelling of three different proteins. This method benefits from easy preparation of these reagents, selectivity for cysteine, and stability after reaction with a commercial tetrazine, which has potential for the routine preparation of protein conjugates for chemical biology studies.     

Rapid polyelectrolyte-based immunofiltration technique for testosterone detection in serum samples

A new immunofiltration assay for testosterone is proposed. During the first step of the assay, testosterone molecules in serum samples compete in solution with the testosterone-peroxidase conjugate for interaction with anti-testosterone antibodies pre-bound to the conjugate between staphylococcal protein A and polymethacrylate polyanion. The reaction mixture is then filtered through a membrane charged with immobilized poly(N-ethyl-4-vinylpyridinium) polycation. The filtration is accompanied by a rapid separation of the polyanion containing complexes due to high-affinity electrostatic interactions. Following removal of unbound compounds the immobilized peroxidase is detected using a substrate that produces an insoluble coloured product. The proposed assay has been shown to combine high speed (20 min) and sensitivity (0.1 ng ml(-1)), and to be applicable for out-of-laboratory conditions. Based on densitometric measurements, the RSD of the assay is calculated to be 3.2-5.1% (n = 4). The proposed assay is 4 times faster than the microplate enzyme immunoassay (ELISA) based on the same immunoreagents. Pre-incubation of the antibody and the polyanion-protein A conjugate at a certain ratio excludes the influence of immunoglobulins from the tested serum samples on the assay results. The polyanion-protein A conjugate can be used as a universal reagent, eliminating the necessity to modify specific antibodies for each immunoassay.     

Geometrically selective synthesis of functionalized beta,beta-disubstituted vinylic sulfoxides by Cu-catalyzed conjugate addition of organozinc reagents to 1-alkynyl sulfoxides

[reaction: see text] A new synthetic method of chiral beta,beta-disubstituted vinylic sulfoxides bearing various functionalities has been developed by employing Cu-catalyzed conjugate addition of an organozinc reagent to chiral 1-alkynyl sulfoxide. Since the reaction proceeds with very high syn-selectivity, both geometric beta,beta-disubstituted vinylic sulfoxides were stereoselectively synthesized by changing the combination of 1-alkynyl sulfoxide and the organozinc reagent.     

Stable Pyrrole‐Linked Bioconjugates through Tetrazine‐Triggered Azanorbornadiene Fragmentation

An azanorbornadiene bromovinyl sulfone reagent for cysteine‐selective bioconjugation has been developed. Subsequent reaction with dipyridyl tetrazine leads to bond cleavage and formation of a pyrrole‐linked conjugate. The latter involves ligation of the tetrazine to the azanorbornadiene‐tagged protein through inverse electron demand Diels–Alder cycloaddition with subsequent double retro‐Diels–Alder reactions to form a stable pyrrole linkage. The sequence of site‐selective bioconjugation followed by bioorthogonal bond cleavage was efficiently employed for the labelling of three different proteins. This method benefits from easy preparation of these reagents, selectivity for cysteine, and stability after reaction with a commercial tetrazine, which has potential for the routine preparation of protein conjugates for chemical biology studies.     

Enantioselective synthesis of a mealybug pheromone with an irregular monoterpenoid skeleton

The first enantioselective synthesis of a mealybug sex pheromone with an unprecedented monoterpenoid skeleton has been accomplished by using a highly diastereoselective conjugate addition of an organocopper reagent to a gamma-alkyl-alpha,beta-unsaturated ester intermediate as the key step.     

Silafunctional compounds in organic synthesis. 28. Conjugate addition of a hydroxymethyl anion synthon to α,β-enones

The title reaction has been achieved by a sequence of the copper-catalyzed conjugate addition of the (allyldimethylsilyl)methyl Grignard reagent, fluorodeallylation and the H₂O₂-oxidation of the carbon-silicon bond therein.     

(BDP)CuH: a "hot" Stryker's reagent for use in achiral conjugate reductions

A ligand-modified, economical version of Stryker's reagent (SR) has been developed based on a bidentate, achiral bis-phosphine. Generated in situ, "(BDP)CuH" smoothly effects conjugate reductions of a variety of unsaturated substrates, including those that are normally unreactive toward SR. Substrate-to-ligand ratios typically on the order of 1000-10000:1 can be used leading to products in high yields.