Name: one-pot microwave-assisted conversion of anomeric nitrate-esters to trichloroacetimidates
Uploaded: 2018-01-15T13:00:00.000+00:00
Duration: 6 min
Description: Watch this Scientific Journal Video about One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates at JoVE.com

著者は、ヴァンダービルト大学や金融支援のための化学生物学研究所を認めるみたいと思います。高分解能質量スペクトル分析のためバークレー エリス氏と教授ジョン ・ マクレーンを認めた

1. 代表的な電子レンジ-脱硝を支援
<ol><li>アジドフェニル硝酸エステルを配置 (1.0 当量、0.2 モル) 8 mL マイクロ波反応瓶で。反応のスケールは、反応の進行に悪影響を及ぼすことがなくいくつかのモルに増加できます。</li>
	<li>20% アセトン (0.1 M、2.0 mL) アジドフェニル硝酸エステルを溶解します。反応容器にピリジン (5.0 当量、0.08 mL、1.0 モル) を追加します。マイクロ波照射バイアルのキャップ、マイクロ波リアクター共振器で反応容器を配置します。</li>
	<li>攪拌と固定保持時間 15 分の 120 ° C でソリューションを照射します。保持時間は、照射が指定温度および結果の圧力で発生するどのくらいの期間を表します。2 分ランプ間報告された温度のすべての反応を加熱します。組み込み赤外線センサーによって温度を監視します。</li>
	<li>15 分後出発原料の消費量を確認するため薄層クロマトグラフィー (TLC) を用いた反応混合物を分析します。1:1 酢酸エチル/ヘキサンを溶離液として使用します。<ol>
<li>セリウム アンモニウム molybate 染色を用いた TLC 板を視覚化します。反応体およびプロダクトの Rfは異なりますが、削減のアルコールは一般に 0.05 を 0.1 低い Rf反応液より。</li>
	</ol>
</li>
</ol>2、trichloroacetimidate の形成
<ol><li>出発原料の完全な消費は、次の航空会社の使用量を削減する溶剤を蒸発します。(ジクロロ メタン) CH2Cl2 (1.0 mL) で希釈し、水層を除去する注射器を使用します。水層を削除すると、氷水浴を使用して 0 の ° C に反応混合物を冷却します。</li>
	<li>次に、反応容器に DBU (10 eq、0.3 mL、1.9 ミリ モル) と 2,2,2 trichloroacetonitrile (50 eq、1.0 mL、10 m モル) を追加します。ベースの 1 相当と 2,2,2 trichloroacetonitrile の 1 と同等の最小値を必要し、両方の試薬が過剰に追加されます。</li>
	<li>周囲温度に温暖化しながら攪拌反応混合物を許可します。出発原料の消費量を確認する TLC による反応を監視します。<ol>
<li>1:1 酢酸エチル/ヘキサンを溶離液として使用します。セリウム アンモニウム molybate 染色を用いた TLC 板を視覚化します。反応体およびプロダクトの Rfは、異なります。</li>
	</ol>
</li>
	<li>開始材料の完全な消費の後回復フラスコに反応混合物を転送し、30 ° C で真空中で混合物を集中溶剤の蒸発は茶色の油に原油淡黄色を提供します。</li>
	<li>溶離液として 1.5 cm クロマトグラフィー コラムと 1:4 酢酸エチル/ヘキサン シリカゲル カラムクロマトグラフィーにより粗製品を浄化します。イミダートの物理的な形を分子から分子へと変わります。</li>
</ol><img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56610/56610fig1v3.jpg"> 図 1.2 アジドフェニル 1 硝酸エステルの 2 アジドフェニル-1 trichloroimidates への 1 つの鍋変換の代表的な例です。<a href="//cloudflare.jove.com/files/ftp_upload/56610/56610fig1v3large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。

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著者は競合する金融興味を持ってないです。

このチュートリアルで説明されているプロトコルは、反応性、役に立つ機能を硝酸エステルに変換するメソッドを提供します。広い意味で安易な日常難しい変換をする可能性があります炭水化物の合成の過程で特定の演習を完了するマイクロ波リアクターを採用します。このチュートリアルで私たちの目標は、マイクロ波照射のコンテキストで炭水化物を処理する方法を示すことです。
<p...

分子生物学の彼らの普及のため、炭水化物は化学合成の長年の目標をされています。1,2,3合成キャンペーンの成功の中核となる糖鎖を構築するグリコシル化反応の正しい展開です。4,5,6,7,8,9,10,11,12当然、グリコシド結合をインストールする方法の大きい数があります。13,14 Koenigs クノール メソッドは最も早く知られている手順の 1 つですし、結合糖塩化または臭化通常重金属 (水銀や銀) 活性化の下でのアルコール成分が含まれます。15関連糖フッ化物向山グループの 1981 年にドナーとして初めて導入され、彼らの高められた熱・化学安定性のための広範なアプリケーションを発見しました。16反応スペクトルの反対側に糖ヨウ化物、他のハロゲン化物よりもはるかに反応であります。特に α 結合型糖鎖形成増加の立体制御反応性が伴っています。17 "haloglycosides"に加えチオグリコシドを発見したワイドなユーティリティ、一部、形成、反応条件と求電子試薬の活性化の多数の安定性の容易にするため。18
上記フォーカス活性化およびアクセプター分子からアルコールによって最終的に転置されているグループを残して潜在的な「非酸素」を含むにアノマー アルコールに変換するメソッド。アノマー酸素活性化シュミット学校で記述として C1 酸素自体を残してグループに変換するのに焦点を当てください。19このメソッドは、最も強力なは、広く化学グリコシル化反応で。Trichloroacetimidate ドナーは、還元糖、炭酸カリウム (K2CO3) または 1, 8-diazabicyclo [5.4.0] undec-7-エン (DBU) などの塩基の存在下で trichloroacetonitrile から容易に用意しています。これらの種は、ルイス酸を用いたアクティブ化されます。20
最近では、我々 は 2 アジドフェニル-1 trichloroacetimidate ドナーがグリカールから直接調製することができますを報告しています。プロセスには、2 つの反応、2 アジドフェニル 1 硝酸エステルからプロシージャを 1 つの鍋が含まれます。21この詳細なプロトコルは、正常に高収率で変換を完了するために専門家を支援するものです。特定の関心の下で電子レンジの熱脱硝焦点を当てて補助暖房のシーケンスの最初のステップです。また有機合成におけるマイクロ波反応を採用にビジュアル チュートリアルを提供してまいります。

<table><tbody><tr><td>230 400 mesh silica gel</td><td>SiliCycle Inc</td><td>R10030B</td><td></td></tr><tr><td>TLC plates</td><td>SiliCycle Inc</td><td>TLG-R10014B-527</td><td></td></tr><tr><td>Ceric ammonium molybdate</td><td>Sigma-Aldrich</td><td>A1343</td><td></td></tr><tr><td>Solvent Still</td><td>Mbraun</td><td>MB-SPS-800</td><td></td></tr><tr><td>Infared spectrometer</td><td>Thermo</td><td>Thermo Electron IR100</td><td></td></tr><tr><td>Nuclear Magnetic Resonance</td><td>Bruker</td><td></td><td>400, 600 MHz</td></tr><tr><td>LC/MS</td><td>Thermo/Dionex</td><td></td><td>Single quad, ESI</td></tr><tr><td>HRMS</td><td>Agilent</td><td>Synapt G2 S HDMS</td><td></td></tr><tr><td>Microwave reactor</td><td>Anton Parr</td><td>Anton Parr G10 Monowave 200</td><td></td></tr><tr><td>DBU</td><td>Sigma-Aldrich</td><td>139009</td><td></td></tr><tr><td>CCl&lt;sub&gt;3&lt;/sub&gt;CN</td><td>Sigma-Aldrich</td><td>T53805</td><td></td></tr><tr><td>Pyridine</td><td>Sigma-Aldrich</td><td>270970</td><td></td></tr><tr><td>Acetone</td><td>Fisher Scientific</td><td>A18-20</td><td>Tech. grade</td></tr><tr><td>Phase separator</td><td>Biotage</td><td>120-1901-A</td><td></td></tr><tr><td>Rotary evaporator</td><td>Buchi</td><td>R-100</td><td></td></tr></tbody></table>

one-pot microwave-assisted conversion of anomeric nitrate-esters to trichloroacetimidates

次の手順の目的は、2-アジドフェニル-1-硝酸-エステルの trichloroacetimidate 糖ドナーへの 1 つの鍋変換のデモを提供することです。アジドフェニル-、glycal のニトロ化、次、マイクロ波照射下で製品 2 アジドフェニル 1 硝酸エステルを加水分解することができます。この変換では、強く求核試薬との反応時間が延長された使用は行われます通常。マイクロ波照射は、試薬と短い反応時間の不在で、加水分解を誘導します。次の脱硝、中間アノマー アルコールは、対応する 2-アジドフェニル-1-trichloroacetimidate に、同じ鍋に変換されます。

3 2 アジドフェニル 1 硝酸エステルのプールに記載の技術を示した。それぞれのケースで反応の最初のステップは、20 分以内で完了しました。
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56610/56610fig2v3.jpg"> 図 2 。加水分解の代表例 (1 -2)、および1の 2 アジドフェニル 1 硝?...

Watch this Scientific Journal Video about One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates at JoVE.com

One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates

1 つの鍋マイクロ波への変換アノマー硝酸エステルの Trichloroacetimidates

2-アジドフェニル-1-硝酸のエステルは、対応する 2-アジドフェニル-1-trichloroacetimidate 1 つの鍋の手順でに変換できます。原稿の目標は、炭水化物の合成におけるマイクロ波リアクターの有用性を示すことです。

The goal of the following procedure is to provide a demonstration of the one-pot conversion of a 2-azido-1-nitrate-ester to a trichloroacetimidate ...

one-pot-microwave-assisted-conversion-anomeric-nitrate-esters-to

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7.4K ビュー.  Vanderbilt University. 2-アジドフェニル-1-硝酸のエステルは、対応する 2-アジドフェニル-1-trichloroacetimidate 1 つの鍋の手順でに変換できます。原稿の目標は、炭水化物の合成におけるマイクロ波リアクターの有用性を示すことです。

ビデオ: One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides (CHIPS)

The direct functionalization of C-H bonds is an important and long standing goal in organic chemistry. Such transformations can be very powerful in order to streamline synthesis by saving steps, time and material compared to conventional methods that require the introduction and removal of activating or directing groups. Therefore, the functionalization of C-H bonds is also attractive for green chemistry. Under oxidative conditions, two C-H bonds or one C-H and one heteroatom-H bond can be transformed to C-C and C-heteroatom bonds, respectively. Often these oxidative coupling reactions require synthetic oxidants, expensive catalysts or high temperatures. Here, we describe a two-step procedure to functionalize indole derivatives, more specifically tetrahydrocarbazoles, by C-H amination using only elemental oxygen as oxidant. The reaction uses the principle of C-H functionalization via Intermediate PeroxideS (CHIPS). In the first step, a hydroperoxide is generated oxidatively using visible light, a photosensitizer and elemental oxygen. In the second step, the N-nucleophile, an aniline, is introduced by Br&#248;nsted-acid catalyzed activation of the hydroperoxide leaving group. The products of the first and second step often precipitate and can be conveniently filtered off. The synthesis of a biologically active compound is shown.

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides CHIPS

A two-step procedure for the synthesis of pharmaceutically active indole-derivatives by C-H functionalization with anilines is described, using photo- and Br&#248;nsted acid catalysis.

中間過酸化物を介した光化学および酸触媒CH機能化による抗ウイルステトラヒドロカルバゾール誘導体の合成（チップ）

The direct functionalization of C-H bonds is an important and long standing goal in organic chemistry. Such transformations can be very powerful in order ...

化学

Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators

In organic chemistry ionic liquids (ILs) have emerged as safe and recyclable reaction solvents. In the presence of a base ILs can be deprotonated to form catalytically active N-Heterocyclic Carbenes (NHCs). Here we have used ILs as precatalysts in the addition of &#945;,&#946;-unsaturated aldehydes to chalcones to form 1,6-ketoesters, incorporating an anti-diphenyl moiety in a highly stereoselective fashion. The reaction has a broad substrate scope and several functional groups and heteroaromatics can be integrated into the ketoester backbone in generally good yields with maintained stereoselectivity. The reaction protocol is robust and scalable. The starting materials are inexpensive and the products can be obtained after simple filtration, avoiding solvent-demanding chromatography. Furthermore, the IL can be recycled up to 5 times without any loss of reactivity. Moreover, the 1,6-ketoester end product is a potent gelator in several hydrocarbon based solvents. The method enables rapid access to and evaluation of a new class of low molecular weight gelators (LMWGs) from recyclable and inexpensive starting materials.

Ionic liquids (ILs) mediate fast, simple and cheap access to 1,6-ketoesters in high diastereoselectivities and good yields. The reaction protocol is robust and the 1,6-ketoesters can be obtained in gram scale after a simple filtration protocol. Moreover, the 1,6-ketoesters are potent gelators in hydrocarbon solvents.

イオン液体によって媒介1,6-ケトエステルの高立体選択的合成：低分子ゲル化剤の新しいクラスへの迅速なアクセスを有効にする三成分の反応

In organic chemistry ionic liquids (ILs) have emerged as safe and recyclable reaction solvents. In the presence of a base ILs can be deprotonated to form ...

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.

の合成のためのプロトコル<em&gt;オルソ</em&gt; -trifluoromethoxylatedアニリン誘導体

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

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; Z</em&gt;、4<em&gt; E</em&gt;） - 電子不足アルケンと酢酸アリルとの合成によるジエナミド

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.

Nの準備-(2-alkoxyvinyl) N- トシル-1,2,3-トリアゾールと置換 Phthalans とフェネチルアミンに後続の変換からサルファ剤

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

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides

The conjugate addition of organometallic reagents to &#945;,&#946;-unsaturated carbonyls represents an important method to generate C&#8211;C bonds in the preparation of all-carbon quaternary centers. Though conjugate additions of organometallic reagents are typically performed utilizing highly reactive organolithium or Grignard reagents, organozinc reagents have garnered attention for their enhanced chemoselectivity and mild reactivity. Despite numerous recent advances with more reactive diorganozinc and mixed diorganozinc reagents, the generation of all-carbon quaternary centers via the conjugate addition of functionalized monoorganozinc reagents remains a challenge. This protocol details a convenient and mild &#8220;one-pot&#8221; preparation and copper mediated conjugate addition of functionalized monoorganozinc bromides to cyclic &#945;,&#946;-unsaturated carbonyls to afford a broad scope of all-carbon quaternary centers in generally excellent yield and diastereoselectivity. Key to the development of this technology is the utilization of DMA as a reaction solvent with TMSCl as a Lewis acid. Notable advantages to this methodology include the operational simplicity of the organozinc reagent preparation afforded by the utilization of DMA as a solvent, as well as an efficient conjugate addition mediated by various Cu(I) and Cu(II) salts. Moreover, an intermediate silyl enol ether can be isolated utilizing a modified workup procedure. The substrate scope is limited to cyclic unsaturated ketones, and the conjugate addition is impeded by stabilized (e.g., allyl, enolate, homoenolate) and sterically encumbered (e.g., neopentyl, o-aryl) monoorganozinc reagents. Conjugate additions to five- and seven-membered rings were effective, albeit in lower yields compared with six-membered ring substrates.

A simple and practical protocol for the efficient conjugate addition of functionalized monoorganozinc bromides to cyclic &#945;,&#946;-unsaturated carbonyls to furnish all-carbon quaternary centers was developed.

官能化 Monoorganozinc 臭化物の共役添加による全炭素4級センターの効率的な合成

The conjugate addition of organometallic reagents to &#945;,&#946;-unsaturated carbonyls represents an important method to generate C&#8211;C bonds in the ...

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

A synthetic process for the preparation of a variety of 1-aryl-1H-pyrazole-5-amines was developed. The microwave-mediated nature of this method makes it efficient in both time and resources and utilizes water as the solvent. 3-Aminocrotononitrile or an appropriate &#945;-cyanoketone is combined with an aryl hydrazine and dissolved in 1 M HCl. The mixture is then heated in a microwave reactor at 150 &#176;C, typically for 10-15 min. The product can be readily obtained by basifying the solution with 10% NaOH and isolating the desired compound with a simple vacuum filtration. The use of water as a solvent in this reaction lends to its ease and utility in production, and this method is easily reproducible with a variety of functional groups. Typical isolated yields range from 70-90%, and reactions can be performed on the milligram to gram scale with little to no change in observed yields. Some of the applications of these molecules and their derivatives include pesticides, anti-malarials, and chemotherapeutics, among many others.

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

1-Aryl-1H-pyrazole-5-amines are prepared from aryl hydrazines combined with either 3-aminocrotononitrile or an &#945;-cyanoketone in a 1 M HCl solution using a microwave reactor. Most reactions are done in 10-15 minutes and pure product can be obtained via vacuum filtration with typical isolated yields of 70-90%.

1-アリル-1 H-ピラゾール-5-アミンのマイクロ波支援調製

A synthetic process for the preparation of a variety of 1-aryl-1H-pyrazole-5-amines was developed. The microwave-mediated nature of this method makes it ...

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyl(tropone)iron

aza-Michael adducts of tricarbonyl(tropone)iron are synthesized by two different methods. Primary aliphatic amines and cyclic secondary amines participate in a direct aza-Michael reaction with tricarbonyl(tropone)iron under solvent-free conditions. Less nucleophilic aniline derivatives and more hindered secondary amines add efficiently to the cationic tropone complex formed by protonation of tricarbonyl(tropone)iron. While the protocol utilizing the cationic complex is less efficient overall for accessing the aza-Michael adducts than the direct, solvent-free addition to the neutral complex, it allows the use of a broader range of amine nucleophiles. Following protection of the amine of the aza-Michael adduct as a tert-butyl carbamate, the diene is decomplexed from the iron tricarbonyl fragment upon treatment with cerium(IV) ammonium nitrate to provide derivatives of 6-aminocyclohepta-2,4-dien-1-one. These products can serve as precursors to diverse compounds containing a seven-membered carbocyclic ring. Because the demetallation requires protection of the amine as a carbamate, the aza-Michael adducts of secondary amines cannot be decomplexed using the protocol described here.

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron

Representative experimental procedures for the addition of amine nucleophiles to tricarbonyl(tropone)iron and subsequent demetallation of the resulting complexes are presented in detail.

トリカルボニル(トロポネ)鉄による6-アミノシクロヘプタ-2,4-dien-1-1誘導体の調製

aza-Michael adducts of tricarbonyl(tropone)iron are synthesized by two different methods. Primary aliphatic amines and cyclic secondary amines participate ...

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

CO2 transformations using a one-pot two-step method are presented herein. The purpose of the method is to give access to a variety of value-added products and notably to generate chiral carbon centers. The crucial first step consists in the selective double hydroboration of CO2 catalyzed by an iron hydride complex. The product obtained with this 4 e- reduction is a rare bis(boryl)acetal, compound 1, which is subjected in situ to three different reactions in a second step. The first reaction concerns a condensation reaction with (diisopropyl)phenylamine affording the corresponding imine 2. In the second and third reaction, intermediate 1 reacts with triazol-5-ylidene (Enders&#39; carbene) to afford compounds 3 or 4, depending on the reaction conditions. In both compounds, C-C bonds are formed, and chiral centers are generated from CO2 as the only source of carbon. Compound 4 exhibits two chiral centers obtained in a diastereoselective manner in a formose-type mechanism. We proved that the remaining boryl fragment plays a key role in this unprecedented stereocontrol. The interest of the method stands on the reactive and versatile nature of 1, giving rise to various complex molecules from a single intermediate. The complexity of a two-step method is compensated by the overall short reaction time (2 h for the larger reaction time), and mild reaction conditions (25 &#176;C to 80 &#176;C and 1 to 3 atm of CO2).

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

CO2 transformations are conducted in a one-pot two-step procedure for the synthesis of complex molecules. The selective 4 e- reduction of CO2 with a hydroborane reductant affords a reactive and versatile bis(boryl)acetal intermediate which is subsequently involved in condensation reaction or carbene-mediated C-C coupling generation.

多彩なCO2の複雑な製品への変革:ワンポット2段階戦略

CO2 transformations using a one-pot two-step method are presented herein. The purpose of the method is to give access to a variety of value-added products ...

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Heteroarylation introduces heteroaryl fragments to organic molecules. Despite the numerous available reactions reported for arylation via transition metal catalysis, the literature on direct heteroarylation is scarce. The presence of heteroatoms such as nitrogen, sulfur and oxygen often make heteroarylation a challenging research field due to catalyst poisoning, product decomposition and the rest. This protocol details a highly efficient direct &#945;-C(sp3) heteroarylation of ketones under microwave irradiation. Key factors for successful heteroarylation include the use of XPhos Palladacycle Gen. 4 Catalyst, excess base to suppress side reactions and the high temperature and pressure achieved in a sealed reaction vial under microwave irradiation. The heteroarylation compounds prepared by this method were fully characterized by proton nuclear magnetic resonance spectroscopy (1H NMR), carbon nuclear magnetic resonance spectroscopy (13C NMR) and high-resolution mass spectrometry (HRMS). This methodology has several advantages over literature precedents including broad substrate scope, rapid reaction time, greener procedure and operational simplicity by eliminating the preparation of intermediates such as silyl enol ether. Possible applications for this protocol include, but are not limited to, diversity-oriented synthesis for the discovery of biologically active small molecules, domino synthesis for the preparation of natural products and ligand development for new transition metal catalytic systems.

Heteroaryl compounds are important molecules utilized in organic synthesis, medicinal and biological chemistry. A microwave-assisted heteroarylation using palladium catalysis provides a rapid and efficient method to attach heteroaryl moieties directly to ketone substrates.

遷移金属触媒を用いたケトンのマイクロ波アシスト直接ヘテロリル化

Heteroarylation introduces heteroaryl fragments to organic molecules. Despite the numerous available reactions reported for arylation via transition metal ...

1 つの鍋マイクロ波への変換アノマー硝酸エステルの Trichloroacetimidates

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