英国皇家空军对这项工作的支持，感谢美国国家科学基金会（CHE-0844946）。

1。合成的SMI（0.1 M） <ol><li>火焰干50毫升的圆底烧瓶中，氩气冲洗。搅拌棒和带隔垫覆盖烧瓶中。称取金属钐（0.2克，1.3毫摩尔），并加至烧瓶中，再次的烧瓶用氩气冲洗。 </li><li>加入10ml干燥的，彻底脱气的四氢呋喃（THF）其次用碘晶体（0.254克，2.0毫摩尔）。通过隔膜加入氩气的气球，这保持对反应Ar气氛的正压。 </li><li>超过3小时，在室温下剧烈搅拌该溶液。正如生成SMI 2溶液通过各种颜色的变化;橙色，然后由黄色（45分钟），以及绿色（1小时），最终变成蓝色。 </li><li>最后的海军蓝色单离子钐已经形成的迹象。为了确保悉数转换后，搅拌溶液至少3小时前使用SMI的合成。 </li></ol> 2。萨marium巴比尔反应 - 六甲基磷酰胺（HMPA）增加<ol><li>为了使SMI 2-六甲基磷酰胺复合物，取新鲜制备的SMI 2（10毫升，0.1M，1.0毫摩尔）在氩气下，通过注射器，在氩气下滴加1.75毫升六甲基磷酰胺（10当量，10毫摩尔）添加。深紫色的颜色形式。 </li><li>分别在：：附加iodododecane（0.45毫摩尔，110微升），在氩气下，3 - 戊酮（0.45毫摩尔，48微升）和2毫升的干燥THF中的清洁，干燥的小瓶。 </li><li>添加底物溶液滴加到SMI 2 /六甲基磷酰胺复合物的混合物。 </li><li>在5分钟内，搅拌，紫色的颜色将开始寻找有云，指示反应结束。 </li><li>反应完成后，暴露在空气中的解决方案，以便淬灭，在搅拌下的颜色进一步改变为黄色。 </li><li>然后将反应通过用饱和氯化铵水溶液洗涤。的溶液加入到一个分液漏斗中，并加入乙醚（5毫升）。剧烈摇动后删除顶部的有机层，增加更多的乙醚。从水层萃取两次，然后合并所有的有机层。 </li><li>洗涤有机层，用饱和硫代硫酸钠水溶液的溶液。卸下底部的水层中，随后用水，然后用最后一次洗涤后用饱和食盐水洗涤。获得最佳的有机层，并浸泡在溶液中存在的水的量的最后的任何添加硫酸镁干燥。 </li><li>通过该解决方案通过一个插头，弗罗里硅土中，以除去过量的六甲基磷酰胺。 </li><li>浓缩的溶液用旋转蒸发器以获得巴尔比耶产品。确定该产品为23 GCMS和1 H-NMR。 </li></ol> 3。巴比尔反应镍钐（ACAC）2催化剂<ol><li>称出镍（acac）的2（1摩尔％，0.01毫摩尔，0.0026克），并加入到一个干净的，干燥的小瓶含有3毫升脱气THF中，在氩气下添加的Ni（acac）的2溶液通过注射器到新鲜制备的s辨率的0.1M SMI 2（1.0毫摩尔，10毫升）。 </li><li>分别在：：附加iodododecane（0.45毫摩尔，110微升），在氩气下，3 - 戊酮（0.45毫摩尔，48微升）和2毫升的干燥THF中的清洁，干燥的小瓶。 </li><li>添加底物溶液滴加到SMI 2 /镍混合物。 </li><li>在15分钟的搅拌，蓝色将消散指示反应结束后，以形成黄绿色的颜色。 </li><li>反应完成后，暴露在空气中的解决方案，以便淬灭，在搅拌下的颜色进一步改变为黄色。工作的反应通过用0.1M水溶液洗涤。盐酸（3毫升）。的溶液加入到一个分液漏斗中，并加入乙醚（5毫升）。 </li><li>洗涤有机层，使用先前描述的协议的水溶液，硫代硫酸钠，水和盐水洗涤，硫酸镁干燥，然后干燥。浓缩溶液获得巴尔比耶产品。该产品可28 GCMS和1 H NMR确定。 </sUP&gt; </li></ol>

<ol>
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没有利益冲突的声明。

这里介绍一个简单的过程使用两种最常见的添加剂产生SMI解决方案及其在有机合成中的应用。这两个例子中描绘的反应机理的认识的重要性，微调的反应SMI 2。知识库的反应机理的支柱，要按照他们的反应的要求，由合成化学家适于允许使用这种试剂。 这种单电子同质化的还原剂是很容易处理，可以从商业渠道购买。虽然上述协议是直线前进的惰性条件下，一些常见故障排除程序是：（一）确保焦磷酸钾，脱气和干，（b）如钐金属有长期暴露在空气中，它可能有一个外层氧化，用研钵和pestal清洁的金属表面暴露的金属研磨，（三）火焰干燥所有玻璃器皿和冷却的氩气下，（四）随着氮，优选氩气惰性气氛中作为购买已被证明与该金属相互作用，（e）在存在下，过量的金属的Sm-有助于保持SMI的浓度如图2所示 ，（六）resublime的碘晶体。

<table border="1"><tbody><tr><td> 的试剂的名称 </td><td> 公司 </td><td> 目录编号 </td><td> 评论（可选） </td></tr><tr><td>金属钐</td><td> ACROS </td><td> 29478-0100 </td><td> -40目，99.9％（METALS BASIS） </td></tr><tr><td> THF </td><td> OmniSolv </td><td> TX0282-1 </td><td>通过创新的技术溶剂净化系统，纯化。另外，它可以通过泵冻融法脱气</td></tr><tr><td>碘</td><td>阿法埃莎</td><td> 41955-22 </td><td> resublimed晶体，99.8％ </td></tr><tr><td> Iodododecane </td><td> ACROS </td><td> 25009-0250 </td><td> 98％ </td></tr><tr><td> 3 - 戊酮</td><td>阿法埃莎</td><td> AAA15297-AE </td><td> 99％ </td></tr><tr><td> HMPA </td><td> Alderich </td><td> H11602 </td><td> 98％;在氩气保护下蒸馏从CaO </td></tr><tr><td> NII 2 </td><td>阿法埃莎</td><td> 22893 </td><td> 99.5％（METALS BASIS） </td></tr></tbody></table>

preparation and use of samarium diiodide (smi2) in organic synthesis: the mechanistic role of hmpa and ni(ii) salts in the samarium barbier reaction

虽然最初认为是一门深奥的试剂2，SMI已经成为一种常见的有机合成化学家的工具。 SMI 2产生通过在THF分子碘的添加金属钐。1,2-3它是一种轻度的和有选择性的单电子还原剂和它的多功能性是一个发起一个宽范围的减少，包括CC键的能力的结果形成和级联或连续的反应。 SMI 2可以减少各种亚砜和砜，氧化膦，环氧化物，烷基和芳基卤化物，羰基化合物，和共轭双键的官能团，包括2-12 SMI-2介导的反应的迷人的功能之一是能够操作的结果的反应，通过选择性地使用的助溶剂或添加剂。在大多数情况下，添加剂是必要的控制的减少速度，与化疗或立体选择性反应。13-14添加剂合作mmonly微调利用SMI 2的反应性可分为三个主要的组：（1）路易斯碱磷酰三胺（HMPA，以及其他的电子给体配体，螯合剂醚，等），（2）质子源（醇类，水等），及（3）无机添加剂（镍（acac）的2，FeCl 3的 ，等）。 了解SMI 2反应的机制和该添加剂的作用，可以利用的试剂在有机合成中的全部潜力。选择的Sm-巴比艾尔反应来说明合成的重要性和机械的作用，两种常见的添加剂：HMPA和Ni（II）在该反应中。的Sm-巴比艾尔反应相似，唯一的区别是，烷基卤化物，羰基，和Sm还原剂同时混合以一锅煮的传统的格利雅反应。1,15实施例的范围内的Sm-的介导巴比艾尔反应的耦合伙伴已有报道，1,3,7,10,12，并已被UT斯达康ilized 16,17以往的研究表明，SMI 2反应的效果的添加剂HMPA增强的减排潜力，通过协调的金属钐中心的SMI 2，产生更强大的，大的自然产品的合成中的关键步骤。 13-14,18空间位阻还原剂19-21和发挥不可或缺的作用，后电子转移促进随后的粘接成形的事件的步骤22在的Sm-巴比艾尔反应在某些情况下，已被证明是HMPA另外激活烷基卤化物通过形成络合物在预平衡步骤。23 镍（II）盐的催化添加剂中频繁使用的Sm-介导的转换。24-27虽然是成功的关键，镍（II）的机械作用，在这些反应中是不知道。最近它已被证明，SMI 2降低镍（II）镍（0），并将该反应，然后进行通过organometallic镍（0）化学28 这些机理研究突出，虽然相同巴比艾尔产品被获得，使用不同的添加剂在SMI 2反应极大地改变机械的反应途径。运行这些SMI的协议引发反应。

图1示出钐巴比艾尔反应。与无添加剂的Sm-介导的反应需要72小时，得到69％的所需产物与剩余的起始原料。与另外的10个或更多当量。 HMPA的反应几乎是定量的，在几分钟之内完成。15,23随着加入1摩尔％的Ni（acac）的2，该反应是在15分钟之内完成，用97％的产率28 当HMPA被添加到SMI 2，共溶剂取代协调的THF以形成SMI 2 -磷酰三胺（HMPA）4。随着更HMPA（6-10当量）的添加，碘化物离子位移外球（ 图2）。19-21机理研究表明，当HMPA是用来在的Sm-巴比艾尔反应中的助溶剂也交互与烷基卤化物基板上形成的复合物，其中拉长的碳 - 卤键，激活的species使它更容易用Sm的减少（ 图3）。的角色HMPA，一种机制，用于与HMPA的Sm-巴尔比耶反应，提出了对通过本详细的了解（ 图4）。23烷基卤化物HMPA预平衡步骤中形成的复合物被减少的Sm / HMPA以形成自由基的速率决定步骤。自由基经历进一步减少，以形成有机钐物种夫妇与羰基和质子化后，得到最终产物。 在的情况下，镍（II）的添加剂，SMI 2最初降低镍（II）镍（0）优先超过减少基板之一。基于动力学和机理的研究，提出以下的机制（ 图5）28由SMI 2还原后，可溶性的Ni（0）烷基卤键形成一个有机镍物种物种插入。的带动下高亲氧性的性质的Sm（III）<html> ，transmetallation以形成有机钐中间的版本，镍（II）的催化循环回。的有机钐与羰基的夫妇，经质子化形成所需的叔醇。有人还观察到，通过形成镍（0）纳米粒子的Ni（II）的Sm-介导的降低，然而，这些颗粒被认为是无效和催化剂失活的源。 <img alt="图1" fo:content-width="4in" fo:src="/files/ftp_upload/4323/4323fig1highres.jpg" src="/files/ftp_upload/4323/4323fig1.jpg" /> 图1。的钐巴比艾尔反应与iodododecane和3 -戊酮。 <img alt="图2" fo:content-width="4in" fo:src="/files/ftp_upload/4323/4323fig2highres.jpg" src="/files/ftp_upload/4323/4323fig2.jpg" /> 图2。SMI 2-HMPA复杂。 ontent的“Fo：保持together.within”页面=“总是”&gt; <img alt="图3" fo:content-width="3.5in" fo:src="/files/ftp_upload/4323/4323fig3highres.jpg" src="/files/ftp_upload/4323/4323fig3.jpg" /> 图3。HMPA和烷基碘络合物。 <img alt="图4" fo:content-width="4.5in" fo:src="/files/ftp_upload/4323/4323fig4highres.jpg" src="/files/ftp_upload/4323/4323fig4.jpg" /> 图4。钐巴比尔反应机制，多余的HMPA。 <img alt="图5" fo:content-width="4in" fo:src="/files/ftp_upload/4323/4323fig5highres.jpg" src="/files/ftp_upload/4323/4323fig5.jpg" /> 图5。钐巴比尔反应体系中，氧化镍（II）建议的机制。

Watch this Scientific Journal Video about Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction at JoVE.com

Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction

二碘化钐（SMI编制一个简单的过程，<sub&gt; 2</sub&gt;）在THF中进行说明。的作用的两个主要的添加剂，即六甲基磷酰胺（HMPA）和Ni（乙酰丙酮）<sub&gt; 2</sub在SM介导的反应是体现在的Sm-巴比尔反应。

二碘化钐的制备和使用（SMI<sub&gt; 2</sub&gt;）在有机合成中：HMPA和镍（II）盐的钐巴尔比耶反应的机理作用

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of ...

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Preparation and Use of Samarium Diiodide (SmI2) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction

32.6K 次观看.  Lehigh University. 二碘化钐（SMI编制一个简单的过程， 2）在THF中进行说明。的作用的两个主要的添加剂，即六甲基磷酰胺（HMPA）和Ni（乙酰丙酮） 2

视频: Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

The development of fluorescent indicators represented a revolution for life sciences. Genetically encoded and synthetic fluorophores with sensing abilities allowed the visualization of biologically relevant species with high spatial and temporal resolution. Synthetic dyes are of particular interest thanks to their high tunability and the wide range of measureable analytes. However, these molecules suffer several limitations related to small molecule behavior (poor solubility, difficulties in targeting, often no ratiometric imaging allowed). In this work we introduce the development of dendrimer-based sensors and present a procedure for pH measurement in vitro, in living cells and in vivo. We choose dendrimers as ideal platform for our sensors for their many desirable properties (monodispersity, tunable properties, multivalency) that made them a widely used scaffold for several biomedical devices. The conjugation of fluorescent pH indicators to the dendrimer scaffold led to an enhancement of their sensing performances. In particular dendrimers exhibit reduced cell leakage, improved intracellular targeting and allow ratiometric measurements. These novel sensors were successfully employed to measure pH in living HeLa cells and in vivo in mouse brain.

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

Fluorescence sensors are powerful tools in life science. Here we describe a methodology to synthesize and use dendrimer-based fluorescent sensors to measure pH in living cells and in vivo. The dendritic scaffold enhances the properties of conjugated fluorescent dyes leading to improved sensing properties.

合成，细胞和交货<em&gt;在体内</em&gt;的树状为基础的pH值传感器应用

The development of  fluorescent indicators represented a revolution for life sciences. Genetically  encoded and synthetic fluorophores with sensing ...

科研

化学

Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents

Amide coupling reactions can be used to synthesize bispyridine-based ligands for use as bridging linkers in multinuclear platinum anticancer drugs. Isonicotinic acid, or its derivatives, are coupled to variable length diaminoalkane chains under an inert atmosphere in anhydrous DMF or DMSO with the use of a weak base, triethylamine, and a coupling agent, 1-propylphosphonic anhydride. The products precipitate from solution upon formation or can be precipitated by the addition of water. If desired, the ligands can be further purified by recrystallization from hot water. Dinuclear platinum complex synthesis using the bispyridine ligands is done in hot water using transplatin. The most informative of the chemical characterization techniques to determine the structure and gross purity of both the bispyridine ligands and the final platinum complexes is 1H NMR with particular analysis of the aromatic region of the spectra (7-9 ppm). The platinum complexes have potential application as anticancer agents and the synthesis method can be modified to produce trinuclear and other multinuclear complexes with different hydrogen bonding functionality in the bridging ligand.

This protocol describes the use of amide coupling reactions of isonicotinic acid and diaminoalkanes to form bridging ligands suitable for use in the synthesis of multinuclear platinum complexes, which combine aspects of the anticancer drugs BBR3464 and picoplatin.

酰胺偶联反应为双吡啶基配体及其络合合成，以白金为双核抗癌药物

Amide coupling reactions can be used to synthesize bispyridine-based ligands for use as bridging linkers in multinuclear platinum anticancer drugs. ...

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

功能化的合成与表征金属 - 有机骨架

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

Preparation and Use of Carbonyl-decorated Carbenes in the Activation of White Phosphorus

Here we present a protocol for the synthesis of two distinct carbonyl-decorated carbenes. Both carbenes can be prepared using nearly identical procedures in multi-gram scale quantities. The goal of this manuscript is to clearly detail how to handle and prepare these unique carbenes such that a synthetic chemist of any skill level can work with them. The two carbenes described are a diamidocarbene (DAC, carbene 1) and a monoamidoaminocarbene (MAAC 2). These carbenes are highly electron-deficient and as such display reactivity profiles that are atypical of more traditional N-heterocyclic carbenes. Additionally, these two carbenes only differ in their electrophilic character and not their steric parameters, making them ideal for studying how carbene electronics influence reactivity. To demonstrate this phenomenon, we are also describing the activation of white phosphorus (P4) using these carbenes. Depending on the carbene used, two very different phosphorus-containing compounds can be isolated. When the DAC 1 is used, a tris(phosphaalkenyl)phosphane can be isolated as the exclusive product. Remarkably however, when MAAC 2 is added to P4 under identical reaction conditions, an unexpected carbene-supported P8&#160;allotrope of phosphorus is isolated exclusively. Mechanistic studies demonstrate that this carbene-supported P8allotrope forms via a [2+2] cycloaddition dimerization of a transient diphosphene which has been trapped by treatment with 2,3-dimethyl-1,3-butadiene.

Here, we present a protocol for the synthesis of two carbonyl-decorated carbenes. The protocol makes these interesting compounds readily available to chemists of all skill levels. In addition to the synthesis of these two carbenes, their use in the activation of white phosphorus is also described.

羰基饰卡宾的白色磷的活化制备方法和用途

Here we present a protocol for the synthesis of two distinct carbonyl-decorated carbenes. Both carbenes can be prepared using nearly identical procedures ...

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts

Ynones are a valuable functional group and building block in organic synthesis. Ynones serve as a precursor to many important organic functional groups and scaffolds. Traditional methods for the preparation of ynones are associated with drawbacks including harsh conditions, multiple purification steps, and the presence of unwanted byproducts. An alternative method for the straightforward preparation of ynones from acyl chlorides and potassium alkynyltrifluoroborate salts is described herein. The adoption of organotrifluoroborate salts as an alternative to organometallic reagents for the formation of new carbon-carbon bonds has a number of advantages. Potassium organotrifluoroborate salts are shelf stable, have good functional group tolerance, low toxicity, and a wide variety are straightforward to prepare. The title reaction proceeds rapidly at ambient temperature in the presence of a Lewis acid without the exclusion of air and moisture. Fair to excellent yields may be obtained via reaction of various aryl and alkyl acid chlorides with alkynyltrifluoroborate salts in the presence of boron trichloride.

The goal of this manuscript is to demonstrate a straightforward method for the preparation of ynones from acyl chloride and potassium alkynyltrifluoroborate salt starting materials. The one-pot reaction proceeds rapidly in the presence of boron trichloride without exclusion of air and moisture.

Ynones从酰氯和钾Alkynyltrifluoroborate盐无金属合成

Ynones are a valuable functional group and building block in organic synthesis. Ynones serve as a precursor to many important organic functional groups ...

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150&#160;nm. The nMST material was found to have a Brunauer-Emmett-Teller (BET) surface area of 285 m2g-1, which is more than an order of magnitude higher than the micron-sized MST. The isoelectric point of the nMST measured 3.34 pH units, which is a pH unit lower than that measured for the micron-size MST. The nMST material was found to serve as an effective ion exchanger under weakly acidic conditions for the preparation of an Au(III)-exchange nanotitanate. In addition, the formation of the corresponding peroxotitanate was demonstrated by reaction of the nMST with hydrogen peroxide.

The surfactant mediated sol-gel synthesis of nanosized monosodium titanate is described, along with preparation of the corresponding peroxide modified material. An ion-exchange reaction with Au(III) is also presented.

纳米尺寸钛酸二氢钠的合成和化学反应

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

超分子胶体的合成与表征

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the development of antibody drug conjugates (ADCs) and nanomedicine, fluorescent microscopy and systems chemistry. For many of these applications, specificity of the bioconjugation method used is of prime concern. The Michael addition of maleimides with cysteine(s) on the target proteins is highly selective and proceeds rapidly under mild conditions, making it one of the most popular methods for protein bioconjugation.
We demonstrate here the modification of the only surface-accessible cysteine residue on yeast cytochrome c with a ruthenium(II) bisterpyridine maleimide. The protein bioconjugation is verified by gel electrophoresis and purified by aqueous-based fast protein liquid chromatography in 27% yield of isolated protein material. Structural characterization with MALDI-TOF MS and UV-Vis is then used to verify that the bioconjugation is successful. The protocol shown here is easily applicable to other cysteine - maleimide coupling of proteins to other proteins, dyes, drugs or polymers.

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

This protocol details the important steps required for the bioconjugation of a cysteine containing protein to a maleimide, including reagent purification, reaction conditions, bioconjugate purification and bioconjugate characterization.

蛋白质生物缀合物的合成<em&gt;通过</em&gt;半胱氨酸马来酰亚胺化学

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the ...

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

A protocol for the synthesis and characterization of diffusive motion of cyclic polymers at the single molecule level is presented.

环状聚合物的合成及其在熔融状态扩散运动的表征在单分子水平

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single ...

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. Detailed and generalized protocols are also presented for testing the catalytic activity of such complexes in arylation and Suzuki-Miyaura cross-coupling reactions. Representative results are shown for the catalytic activity of the four complexes in arylation and Suzuki-Miyaura type reactions. For each of the reactions investigated, at least one of the four complexes successfully catalyzed the reaction, qualifying them as promising candidates for catalysis of many carbon-carbon bond-forming reactions. The protocols presented are general enough to be adapted for the synthesis, purification and catalytic activity testing of new palladium N-heterocyclic carbene complexes.

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. The complexes were tested for catalytic activity in arylation and Suzuki-Miyaura reactions. For each reaction investigated, at least one of the four complexes successfully catalyzed the reaction.

钯<em&gt;ñ</em&gt; - 杂环碳烯配合物：苯并咪唑盐的合成和碳 - 碳键合反应中的催化活性

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from ...