我们承认来自情报局 (ANR-15-CE29-0020-01, 活动), CNRS, ICMR, 大学 de 兰斯香槟住宿, ENSCM 和 ICGM 的财政支持。我们感谢卡琳马查多和安东尼. 罗伯特的帮助与磁共振和核磁共振分析。

1. Glovebox 外的起始材料的制备
<ol><li>准备必要的设备: 用磁力搅拌棒、真空/惰性气体线 (氩或氮气) 和磁力搅拌器的烘箱干 Schlenk 管。</li>
	<li>根据文献13准备 trifluoromethylated benzofulvene。</li>
	<li>称量出 trifluoromethylated benzofulvene (177 毫克, 0.65 毫摩尔), 并加入一个烤箱干燥 Schlenk 管配备了磁力搅拌棒。</li>
	<li>用带有聚四氟乙烯衬垫的塑料螺钉盖关闭 Schlenk 管, 并连接至真空线。</li>
	<li>开始搅拌和应用真空干燥 benzofulvene 10 分钟。然后, 用氩/氮气释放真空, 再应用真空。重复此过程3次。最后, 用氩/氮气填充 Schlenk 管, 并紧密地关闭。</li>
	<li>把 Schlenk 管放在氩/氮气的手套盒里。</li>
</ol>2. Glovebox 内新提交的镝金属的制备
<ol><li>准备必要的设备: 用称量天平、金属锉、钳子、铝箔、镊子、刮刀、试管和2橡胶隔膜在氩/氮气下的手套箱。</li>
	<li>制备化学品: 金属镝和无水 AlCl3
</li>
	<li>插入 Schlenk 管与 benzofulvene, 试管和2橡胶隔膜进入 glovebox 根据您的小组的一般做法为处理 glovebox,例如,为一个小房间应用真空1分钟然后释放与氩/氮气三次。</li>
	<li>把一块铝箔放在天平上, 一张放到 glovebox 地板上的盘子上, 以便归档。</li>
	<li>在钳子的帮助下紧紧地握住镝金属, 并通过用金属锉锉来获得光亮的金属表面, 从而去除上面不活跃的层。扔掉这个金属。 注: (1) 使用大型金属件进行归档, 避免钳和文件之间的接触, 以免污染镝金属与其他金属。(2) 对每种镧系金属使用不同的金属文件, 以避免交叉污染。(3) 废弃金属粉末应在手套箱外单独淬火, 使用 dil. HCl 溶液。 注意: 镝与蒽醌的反应是放热的, 产生氢气, 因此在被冰浴包围的开瓶中淬火镝。</li>
	<li>准备新提交的镝金属 (82 毫克, 0.50 毫摩尔), 添加到 Schlenk 管, 并关闭管与橡胶隔膜。</li>
	<li>将无水 AlCl3 (200 毫克, 1.5 毫摩尔) 称量成试管, 用橡胶隔膜关闭管。</li>
	<li>从手套箱中取出 Schlenk 管和试管。</li>
</ol>3. 在 Glovebox 外启动 C F 活化反应
<ol><li>准备必要的设备: 真空/惰性气体线 (氩或氮气), 磁性搅拌器和干2毫升注射器与针。</li>
	<li>准备化学品: 新鲜蒸馏干 THF 和碘。</li>
	<li>将 Schlenk 管夹在磁搅拌器上方的通风罩内, 并连接至真空线。在氩/氮气的正流动下打开 Schlenk 管前, 执行三次真空/惰性气体循环。启动磁力搅拌器。</li>
	<li>用 AlCl3在通风罩中夹住试管, 在氩/氮气的正流动下通过针连接到惰性气体线。</li>
	<li>在正氩/氮气流下加入催化量的碘 (10-12 毫克) 到 Schlenk 管。</li>
	<li>用针在氩/氮气下清除干2毫升注射器</li>
	<li>服用1.5 毫升新鲜蒸馏干 THF 使用清除注射器和增加0.5 毫升到 Schlenk 管获得一个深褐色溶液 (碘的颜色在 THF)。</li>
	<li>将剩余的1.0 毫升 THF 滴到试管中, AlCl3, 这将导致轻微的黄色溶液。 注: 根据 AlCl3的质量, 添加 THF 可以或多或少放热。</li>
	<li>虽然仍然温暖, 转移这个 AlCl3解决方案从试管到 Schlenk 管使用注射器。</li>
	<li>允许反应搅拌, 直到充分消耗 benzofulvene。最初, 深褐色的颜色将消失, 给一个黄色的解决方案, 随着时间的推移将变成一个深绿色混浊的解决方案。</li>
	<li>在氩/氮的正流动下, 用毛细管将反应混合物的样品取样, 检查1小时后薄层层析 (TLC) 的反应。以石油醚为淋洗。 注: 在薄层色板上的起始 benzofulvene 为亮黄色, 可轻易观察到其消失。</li>
</ol>4. 添加 Nitroalkene
<ol><li>根据文献16准备 4-methoxyphenylnitroalkene。</li>
	<li>在试管中称 4-methoxyphenylnitroalkene (90 毫克, 0.50 毫摩尔), 用橡胶塞子关闭管子, 通过针连接将其干燥在真空线上。</li>
	<li>在反应混合物中 benzofulvene 消失后 (经薄层分析证实), 在氩/氮正流动下加入干 nitroalkene Schlenk 管。反应混合物会改变颜色为黄绿色。</li>
	<li>监测反应的薄层色谱分析, 直到充分消耗的 nitroalkene (通常1小时)。以石油醚/乙酸乙酯95/5 为淋洗。</li>
</ol>5. 检查和纯化
<ol><li>用20毫升乙醚稀释反应混合物, 在开 Schlenk 管中用5毫升1摩尔水溶液将其淬火。 注意: 残余镝与蒽醌的反应是放热的, 产生氢气, 这可能会导致 Schlenk 中的压力积聚。因此, 在良好的油烟罩下, 在开 Schlenk 中淬火反应。</li>
	<li>淬火后的反应, 转移到一个部位漏斗。</li>
	<li>在锥形瓶中收集有机相。用10毫升乙醚洗涤水相2次, 在锥形瓶中收集有机相。</li>
	<li>干燥的有机相超过 MgSO4, 过滤成一个预称量瓶, 并集中在减少压力的旋转蒸发器, 以获得原油产品作为一个橙色棕油。</li>
	<li>以石油醚为淋洗, 用硅凝胶柱层析法提纯粗品, 去除非极性水解产物。增加极性高达10/1 石油醚/乙酸乙酯给新的含硝基的 difluoroalkenes。 注意: 在长柱上执行柱层析和缓慢增加极性时, 可以将 diastereoisomers 分离, 以供分析之用。</li>
</ol>

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作者没有什么可透露的。

该协议涉及高反应性, 空气和湿度敏感的镧系金属的工作。因此, 整个反应过程必须在干惰性气体下进行, 所有起动材料, 包括溶剂, 在使用前必须非常干净和干燥。
在购买已提交的金属方面有两个好处: (一) 采购件或锭的经济大大增加, (二) 新提交的金属由于表面钝化造成的减少而更具反应性。由储存的金属。
所述过程有两个主要的关键步骤: (i) 通过提交?...

自二十世纪七十年代代末以来, 稀土金属在有机合成中已被零星使用。最初, 这些强还原剂, 其氧化还原电位在约-2.3 V 的3 +/里, 主要用于桦木型的芳香化合物的减少和频哪醇偶联反应。二十世纪八十年代对稀土金属的可用性和纯度的提高, 以及开发处理空气和湿气敏感化合物的方法和设备, 导致了稀土金属的新应用。直接从 Sm 金属和 diiodoethane 或碘中广泛使用的 SmI2的制备是镧系化学2的突破。近年来, 对镧系金属的新的反应性模式进行了描述, 例如, 烯卤化物与羰基化合物的 Barbier 型反应,包括二芳基酮4或酰的还原偶联反应。氯化物5, 选择性环丙烷化反应6, 和镧系金属的组合4茂金属7,8。这些研究表明, 镧系金属具有很好的功能基团耐受性, 它们的反应能力会随稀土系列的不同而变化, 使它们成为有机转化过程中微调反应条件的合适试剂。
在40年9、10、11的芳香和脂肪族碳氟键的活化反应中, 研究了 Organolanthanide 配合物和无机镧系盐。在 2014年, 第一次报告的 C F 活化使用元素镱金属出现12。它显示了 Yb 与 pentafluorobenzene 的选择性反应, 以支付 tetrafluorobenzene 和 YbF2。最近, 我们已经表明, 各种镧系金属可以与 trifluoromethylated benzofulvenes 在氯化铝的存在, 以获得ε, difluoropentadienylmetal 络合物, 有选择地反应与广泛的醛, 以新的difluoroalkenes (图 1)13。结果表明, 金属镝和氯化铝的结合给出了最高的产量和最佳的选择性。我们在这里提出了这项工作的扩展使用 nitroalkenes 作为 electrophiles14, 导致 regioselectively 到一个新的类 difluoroalkenes15。

<table><tbody><tr><td>Dysprosium ingot</td><td>Strem</td><td>93-6637</td><td>Store under nitrogen/argon</td></tr><tr><td>Anhydrous aluminum chloride</td><td>Alfa Aesar</td><td>88488</td><td>Store under nitrogen/argon</td></tr><tr><td>Iodine 99.5% for analysis</td><td>Across Organics</td><td>212491000</td><td></td></tr><tr><td>THF GPR Rectapur</td><td>VWR Chemicals</td><td>28552.324</td><td>Dried and distilled over Na/benzophenone before use</td></tr><tr><td>Glovebox</td><td>MBraun</td><td></td><td>Under nitrogen atmosphere</td></tr></tbody></table>

application of elemental lanthanides in the selective c-f activation of trifluoromethylated benzofulvenes providing access to various difluoroalkenes

在 polyfluorinated 芳香分子中或在含三氟甲基基板上选择性活化一碳-氟键, 可获得具有独特含氟分子的可能性, 而其他合成通路。在各种金属中, 可以通过 C f 活化, 镧 (ln) 是良好的候选, 因为它们形成了强大的 F 型债券。镧系金属是具有氧化还原电位的强还原剂, 在约-2.3 V 的3 +/中, 可与镁2 +/毫克氧化还原偶的值相媲美。此外, 镧系金属具有很好的功能基团耐受性, 它们的活性可以随稀土系列的不同而变化, 使它们适合于有机和金属化转化过程中微调反应条件的合适试剂。然而, 由于他们的 oxophilicity, 镧反应容易与氧气和水, 因此需要特殊条件的储存, 处理, 准备和活化。这些因素限制了在有机合成中的广泛应用。在这里, 我们介绍了金属镝是如何使用 glovebox 和 Schlenk 技术在无水条件下进行新鲜制备的。新提交的金属与氯化铝结合, 在 trifluoromethylated benzofulvenes 启动选择性的 C F 活化。由此产生的反应中间体与 nitroalkenes 反应, 以获得一个新的 difluoroalkenes 家族。

这种镧系介导的 C F 活化过程随后与 nitroalkenes 的反应, 可以方便地进入含有硝基基团的新 difluoroalkenes。图 2描述了一个看似合理的反应机制。与我们以前的工作使用醛作为 electrophiles (图 1)13, nitroalkenes 支付 13-disubstituted 茚产品 regioselectively。这可能是由 nitroalkene 组的较大空间体积来解释的。
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Watch this Scientific Journal Video about Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes at JoVE.

Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes

本协议描述了惰性气氛下元素镧的制备及其在含有 trifluoromethylated benzofulvenes 的选择性 C F 活化过程中的应用。

元素镧在选择性 c-F 活化 Trifluoromethylated Benzofulvenes 中的应用提供各种 Difluoroalkenes 的访问

The selective activation of one carbon-fluorine bond in polyfluorinated aromatic molecules or in trifluoromethyl-containing substrates offers the ...

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Chemistry

6.4K 次观看.  Université de Reims Champagne Ardenne. 本协议描述了惰性气氛下元素镧的制备及其在含有 trifluoromethylated benzofulvenes 的选择性 C F 活化过程中的应用。

视频: Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes

The procedures described in this article involve the synthesis and isolation of hypervalent iodonium alkynyl triflates (HIATs) and their subsequent reactions with azides to form cyanocarbene intermediates. The synthesis of hypervalent iodonium alkynyl triflates can be facile, but difficulties stem from their isolation and reactivity. In particular, the necessity to use filtration under inert atmosphere at -45 &deg;C for some HIATs requires special care and equipment. Once isolated, the compounds can be stored and used in reactions with azides to form cyanocarbene intermediates. 
The evidence for cyanocarbene generation is shown by visible extrusion of dinitrogen as well as the characterization of products that occur from O-H insertion, sulfoxide complexation, and cyclopropanation. A side reaction of the cyanocarbene formation is the generation of a vinylidene-carbene and the conditions to control this process are discussed. There is also potential to form a hypervalent iodonium alkenyl triflate and the means of isolation and control of its generation are provided. The O-H insertion reaction involves using a HIAT, sodium azide or tetrabutylammonium azide, and methanol as solvent/substrate. The sulfoxide complexation reaction uses a HIAT, sodium azide or tetrabutylammonium azide, and dimethyl sulfoxide as solvent. The cyclopropanations can be performed with or without the use of solvent. The azide source must be tetrabutylammonium azide and the substrate shown is styrene.

Herein is described the synthesis, isolation, and reactions of hypervalent iodonium alkynyl triflates (HIATs) with azides to generate cyanocarbenes. The procedures will involve air-sensitive and cryogen techniques, including cold filtration under an inert atmosphere. Handling and safety of the synthesized compounds will also be discussed.

高价碘鎓炔基三氟甲磺酸酯的生成Cyanocarbenes的合成应用

The procedures described in this article involve the synthesis and isolation of hypervalent iodonium alkynyl triflates (HIATs) and their subsequent ...

科研

化学

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 ...

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of trifluoromethoxylated aromatic compounds remains a formidable challenge in organic synthesis. Conventional approaches often suffer from poor substrate scope, or require use of highly toxic, difficult-to-handle, and/or thermally labile reagents. Herein, we report a user-friendly protocol for the synthesis of methyl 4-acetamido-3-(trifluoromethoxy)benzoate using 1-trifluoromethyl-1,2-benziodoxol-3(1H)-one (Togni reagent II). Treating methyl 4-(N-hydroxyacetamido)benzoate (1a) with Togni reagent II in the presence of a catalytic amount of cesium carbonate (Cs2CO3) in chloroform at RT afforded methyl 4-(N-(trifluoromethoxy)acetamido)benzoate (2a). This intermediate was then converted to the final product methyl 4-acetamido-3-(trifluoromethoxy)benzoate (3a) in nitromethane at 120 &#176;C. This procedure is general and can be applied to the synthesis of a broad spectrum of ortho-trifluoromethoxylated aniline derivatives, which could serve as useful synthetic building blocks for the discovery and development of new pharmaceuticals, agrochemicals, and functional materials.

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

An operationally simple procedure for the synthesis of ortho-trifluoromethoxylated aniline derivatives via a two-step sequence of O-trifluoromethylation of N-aryl-N-hydroxyacetamide followed by thermally induced intramolecular OCF3-migration is reported.

协议的合成<em&gt;邻</em&gt; -trifluoromethoxylated苯胺类化合物

Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of ...

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene

A reliable, intermediate scale preparation of 1,2,3,4,5-pentamethylcyclopentadiene (Cp*H) is presented, based on modifications of existing protocols that derive from initial 2-bromo-2-butene lithiation followed by acid mediated dienol cyclization. The revised synthesis and purification of the ligand avoids the use of mechanical stirring while still permitting access to significant quantities (39 g) of Cp*H in good yield (58%). The procedure offers other additional benefits, including a more controlled quench of excess lithium during the production of the intermediate heptadienols and a simplified isolation of Cp*H of sufficient purity for metallation with transition metals. The ligand was subsequently used to synthesize [Cp*MCl2]2 complexes of both iridium and ruthenium to demonstrate the utility of the Cp*H prepared and purified by our method. The procedure outlined herein affords substantial quantities of a ubiquitous ancillary ligand support used in organometallic chemistry while minimizing the need for specialized laboratory equipment, thus providing a simpler and more accessible entry point into the chemistry of 1,2,3,4,5-pentamethylcyclopentadiene.

Reliable, intermediate scale preparation of 1,2,3,4,5-pentamethylcyclopentadiene (Cp*H) is presented. The revised protocol for the synthesis and purification of the ligand minimizes the need for specialized laboratory equipment while simplifying reaction workups and product purification. Use of Cp*H in the synthesis of [Cp*MCl2]2 complexes (M = Ru, Ir) is also described.

访问有价值的配体为支持过渡金属:1,2,3,4,5-五甲基环戊二烯的一种改进，中级规模制备

A reliable, intermediate scale preparation of 1,2,3,4,5-pentamethylcyclopentadiene (Cp*H) is presented, based on modifications of existing protocols that ...

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Direct cross-coupling between two alkenes via vinylic C-H bond activation represents an efficient strategy for the synthesis of butadienes with high atomic and step economy. However, this functionality-directed cross-coupling reaction has not been developed, as there are still limited directing groups in practical use. In particular, a stoichiometric amount of oxidant is usually required, producing a large amount of waste. Due to our interest in novel 1,3-butadiene synthesis, we describe the ruthenium-catalyzed olefination of electron-deficient alkenes using allyl acetate and without external oxidant. The reaction of 2-phenyl acrylamide and allyl acetate was chosen as a model reaction, and the desired diene product was obtained in 80% isolated yield with good stereoselectivity (Z,E/Z,Z = 88:12) under optimal conditions: [Ru(p-cymene) Cl2]2 (3 mol %) and AgSbF6 (20 mol %) in DCE at 110 &#186;C for 16 h. With the optimized catalytic conditions in hand, representative &#945;- and/or &#946;-substituted acrylamides were investigated, and all reacted smoothly, regardless of aliphatic or aromatic groups. Also, differently N-substituted acrylamides have proven to be good substrates. Moreover, we examined the reactivity of different allyl derivatives, suggesting that the chelation of acetate oxygen to the metal is crucial for the catalytic process. Deuterium-labeled experiments were also conducted to investigate the reaction mechanism. Only Z-selective H/D exchanges on acrylamide were observed, indicating a reversible cyclometalation event. In addition, a kinetic isotope effect (KIE) of 3.2 was observed in the intermolecular isotopic study, suggesting that the olefinic C-H metalation step is probably involved in the rate-determining step.

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

The ruthenium-catalyzed olefination of electron-deficient alkenes with allyl acetate is described here. By using aminocarbonyl as a directing group, this external oxidant-free protocol has high efficiency and good stereo- and regioselectivity, opening a novel synthetic route to (Z,E)-butadiene skeletons.

（2<em&gt;ž</em&gt;，4<em&gt;电子</em&gt;） - 通过电子缺陷烯烃与烯丙基乙酸酯的烯化反应制备二烯酰胺

Direct cross-coupling between two alkenes via vinylic C-H bond activation represents an efficient strategy for the synthesis of butadienes with high ...

Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

Decomposition of N-tosyl-1,2,3-triazoles with rhodium(II) acetate dimer in the presence of alcohols forms synthetically versatile N-(2-alkoxyvinyl)sulfonamides, which react under a variety of conditions to afford useful N- and O-containing compounds. Acid-catalyzed addition of alcohols or thiols to N-(2-alkoxyvinyl)sulfonamide-containing phthalans provides access to ketals and thioketals, respectively. Selective reduction of the vinyl group in N-(2-alkoxyvinyl)sulfonamide-containing phthalans via hydrogenation yields the corresponding phthalan in good yield, whereas reduction with sodium bis(2-methoxyethoxy)aluminumhydride generates a ring-opened phenethylamine analogue. Because the N-(2-alkoxyvinyl)sulfonamide functional group is synthetically versatile, but often hydrolytically unstable, this protocol emphasizes key techniques in preparing, handling, and reacting these pivotal substrates in several useful transformations.

Preparation of N-2-alkoxyvinylsulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

Representative experimental procedures for the synthesis of N-(2-alkoxyvinyl)sulfonamides and subsequent conversion to phthalan and phenethylamine derivatives are presented in detail.

准备n-(2-alkoxyvinyl) 磺胺从n-tosyl-1,2,3-triazoles 和随后转换为取代 Phthalans 和 Phenethylamines

Decomposition of N-tosyl-1,2,3-triazoles with rhodium(II) acetate dimer in the presence of alcohols forms synthetically versatile ...

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species

&#945;-Functionalization of ketones via umpolung of enolates by hypervalent iodine reagents is an important concept in synthetic organic chemistry. Recently, we have developed a two-step strategy for ketone enolate umpolung that has enabled the development of methods for chlorination, azidation, and amination using azoles. In addition, we have developed C-C bond&#8211;forming arylation and allylation reactions. At the heart of these methods is the preparation of the intermediate and highly reactive enolonium species prior to addition of a reactive nucleophile. This strategy is thus reminiscent of the preparation and use of metal enolates in classical synthetic chemistry. This strategy allows the use of nucleophiles that would otherwise be incompatible with the strongly oxidizing hypervalent iodine reagents. In this paper we present a detailed protocol for chlorination, azidation, N-heteroarylation, arylation, and allylation. The products include motifs prevalent in medicinally active products. This article will greatly assist others in using these methods.

A two step one-pot protocol for the umpolung of ketone enolates to enolonium species and addition of a nucleophile to the &#945;-position is described. Nucleophiles include chloride, azide, azoles, allyl-silanes, and aromatic compounds.

Enolonium 种极性转换酮功能化的两步协议

&#945;-Functionalization of ketones via umpolung of enolates by hypervalent iodine reagents is an important concept in synthetic organic chemistry. ...

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

We present the chemoselective synthesis of 1-(iodoethynyl)-4-methylbenzene, 1-(1,2-diiodovinyl)-4-methylbenzene, and 1-methyl-4-(1,2,2-triiodovinyl)benzene as representative examples for the practical chemoselective preparation of 1-iodoalkynes, 1,2-diiodoalkenes, and 1,1,2-triiodoalkenes from the chemoselective iodination of terminal alkynes mediated by hypervalent-iodine reagents. The chemoselectivity was confirmed by using p-tolylethyne as a model substrate to screen a variety of iodine sources and/or the hypervalent-iodine reagents. A combination of tetrabutylammonium iodide (TBAI) and (diacetoxyiodo)benzene (PIDA) selectively generates 1-iodoalkynes, while a combination of KI and PIDA generates 1,2-diiodoalkenes. A one-pot synthesis based on both TBAI-PIDA and KI-PIDA yields the corresponding 1,1,2-triiodoalkenes. These protocols were subsequently applied to the synthesis of synthetically important aromatic and aliphatic 1-iodoalkynes, 1,2-diiodoalkenes, and 1,1,2-triiodoalkenes, which were obtained in good yield with excellent chemoselectivity.

Herein, detailed protocols for the oxidative iodination of terminal alkynes using hypervalent-iodine reagents are presented, which chemoselectively afford 1-iodoalkynes, 1,2-diiodoalkenes, and 1,1,2-triiodoalkenes.

基于末端碘氧化炔烃的 1-Iodoalkynes、12-Diiodoalkenes、11、2 Triiodoalkenes 的 Chemoselective 制备

We present the chemoselective synthesis of 1-(iodoethynyl)-4-methylbenzene, 1-(1,2-diiodovinyl)-4-methylbenzene, and ...

Easy Access to Aliphatic Sulfonamides using Sulfamoyl Chlorides Under Visible Light Activation

Sulfonamides are prevalent motifs in marketed drugs and natural products. Their synthesis represents a great interest to the pharmaceutical industry, due to their unique biological properties. Recently, several methods for the synthesis of aryl sulfonamides have been developed, but little effort has focused on developing one-step methodologies to access sulfonamides flanked by two alkyl groups. This protocol describes a practical and facile method for the net hydrosulfamoylation of electron-deficient alkenes using sulfamoyl chlorides as radical precursors under blue-light activation. This practical and cost-effective methodology is performed in the presence of the metal-free photocatalyst Eosin Y and uses light as a clean and traceless energy source. The procedure is scalable, displays a broad functional group tolerance, and can be applied for late-stage functionalization. All reagents used in this protocol are commercially available. Simple reaction set-up, the absence of work-up and easy purification, demonstrate the convenience of this protocol. The reaction is best applied to electron-deficient alkenes.

<meta charset="utf8"></head><body>在可见光活化下使用磺胺酰氯轻松获得脂肪族磺胺类药物

Presented here is a protocol for the easy synthesis of aliphatic sulfonamides using sulfamoyl chlorides, (TMS)3SiH and Eosin Y under blue-light irradiation.

在可见光活化下使用磺胺酰氯轻松获得脂肪族磺胺类药物

Sulfonamides are prevalent motifs in marketed drugs and natural products. Their synthesis represents a great interest to the pharmaceutical industry, due ...

元素镧在选择性 c-F 活化 Trifluoromethylated Benzofulvenes 中的应用提供各种 Difluoroalkenes 的访问

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此视频中的章节

高价碘鎓炔基三氟甲磺酸酯的生成Cyanocarbenes的合成应用

Ynones从酰氯和钾Alkynyltrifluoroborate盐无金属合成

协议的合成

访问有价值的配体为支持过渡金属:1,2,3,4,5-五甲基环戊二烯的一种改进，中级规模制备

（2

准备n-(2-alkoxyvinyl) 磺胺从n-tosyl-1,2,3-triazoles 和随后转换为取代 Phthalans 和 Phenethylamines

Enolonium 种极性转换酮功能化的两步协议

基于末端碘氧化炔烃的 1-Iodoalkynes、12-Diiodoalkenes、11、2 Triiodoalkenes 的 Chemoselective 制备

在可见光活化下使用磺胺酰氯轻松获得脂肪族磺胺类药物

在可见光活化下使用磺胺酰氯轻松获得脂肪族磺胺类药物