This work was funded by the Spanish Ministerio de Econom&#236;a y Competitividad (CTQ 2013-41067-P). H.B. acknowledge with thanks a MEC-FPI grant.

1.機能化 2,15-Dimethylhexahelicene <ol><li> 2,15-dimethylhexaheliceneの二臭素 <ol><li>の30％と（過酸化ベンゾイル（BPO）の2,15-dimethylhexaheliceneの0.356グラム（1.0ミリモル）に、新たに再結晶のNブロモスクシンイミド（NBS）の0.374グラム（2.1ミリモル）および24mgの（0.07ミリモル）を計量し、70％の重量安定剤としての水）。磁気攪拌棒を備えた100ミリリットルシュレンクフラスコに、全ての固体を置きます。シュレンクラインに不活性ガスで補充続いガス排気の3サイクルにより窒素雰囲気下に置きました。 </li><li>四塩化炭素（CCl 4）の21ミリリットルを追加します。ドガ溶剤の大規模な損失を防ぐために激しく撹拌しながら、慎重にと同じ避難/補充処理（ステップ1.1.1）によって溶液。 </li><li>還流下での加熱（77℃）で4時間油浴との混合物。 1 H-核磁気共鳴（NMR）によって反応を確認してください。 3.7 ppm以下および4.0 ppmの笙との間にダブレットULDが表示されます。グループ（ 図1） -彼らはジアステレオ-CH 2の存在を示します。 </li><li>一度完成し、混合物を室温まで冷却し、真空下で溶媒を除去します。ポンプの汚染を避けるために液体窒素を充填したトラップを設定します。 </li><li> 、30mlのジクロロメタン（DCM）中の粗を再溶解丸底フラスコに移し、シリカゲルの4グラムと混合（典型的には、粗体重を5倍追加します）。ロータリーエバポレーターで混合物を濃縮。 </li><li>移動相として：その間に、ヘキサン/酢酸エチル（5 95）とあらかじめ混合のSiO 2ゲルカラム（20センチメートルおよび4.5センチ厚さの周りの長さ）を入力します。カラムの上部に混合物を追加し、砂の層（2センチ）を追加します。 </li><li>慎重に新たな移動相に注ぎ、試験管（通常、チューブあたり20ミリリットルと予想される生成物の溶出に近い4ミリリットル）で画分を収集することにより、クロマトグラフィーを行います。薄層クロマトグラフィーで分画をチェックUV光の下で画像：同じ移動相（5ヘキサン/酢酸エチル95）と（TLC）。予想される生成物（ 図4b）は、すべての望んでいた画分を合わせ、ロータリーエバポレーターで溶媒を除去した後、黄色の油として0.35の保持因子（RF）で溶出する必要があります。 334 mgを（収率65％）得られるはずです。 注：すべてのシュレンク技術、今からとても広くプロトコルのほとんどで利用される加熱し、カラムクロマトグラフィーの設定のためのオイルバスの使用は、それらを詳細に説明しませんとだけいくつかのコメント、必要なときに、意志与えられます。 </li></ol></li></ol><img alt="図1" src="/files/ftp_upload/53954/53954fig1.jpg" /> 図 1 2,15 の 1 H-NMRスペクトル（500 MHzでCDCl 3 中 ）。 -。2 -CHに対応するdimethylhelicene（上）と2 時間後に採取したアリコート新しい信号、 -は、赤い円（下部）に示されている。 <a href="https://www.jove.com/files/ftp_upload/53954/53954fig1large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a> <ol start="2"><li> 2,15 -ビスの合成（アジドメチル）hexahelicene <ol><li> 2,15ビス（ブロモメチル）hexaheliceneとアジ化ナトリウムの0.390グラム（6ミリモル）を0.103グラム（0.2ミリモル）を量ります。磁気棒を装備し、窒素雰囲気下に置く50ミリリットルシュレンクフラスコに、両方の固形物を置きます。 </li><li>水5.2ミリリットル（H 2 O）とテトラヒドロフラン（THF）8.6 mlと混合し、シュレンクフラスコに溶剤の混合物を注ぎます。ソリューションを脱気。 </li><li> 3時間還流（65℃）で加熱します。 1 H-NMRで反応を確認してください。 -CH 2 -の信号は3.75 ppmで（ 図2）に移行する必要があります。 </li><li>その後、クー混合物を室温にダウンリットル、真空下でTHFを除去。 H 2 O 50mlで希釈</li><li>分液漏斗に混合物を移し、DCM 40mlで3回抽出します。すべての有機相を合わせ、純粋なH 2 O（50ml）で洗浄します。 </li><li> 2,15ビス（アゾメチル）hexaheliceneに対応するRF = 0.38で黄色の油状物を得、移動相としてヘキサン/酢酸エチル（85:15）を用いるシリカゲルカラムクロマトグラフィーにより粗精製し（ 図5b）。 70 mgを（収率80％）得られるはずです。 </li></ol></li></ol><img alt="図2" src="/files/ftp_upload/53954/53954fig2.jpg" /> 図 2：1 H-NMRスペクトル（500 MHzのは、CDCl 3 中 ）4 B（上）と分量 のは 3時間 後に採取しました（下）。脂肪族地域の変化に注意してください。 <a href="https://www.jove.com/files/ftp_upload/53954/53954fig2large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a> コランニュレンの2官能<ol><li> コランニュレンのMonobromination <ol><li>コランニュレンの0.125グラム（0.5ミリモル）に、新たに再結晶NBSの89ミリグラム（0.5ミリモル）および塩化金（III）水和物17mgの重量を量ります。 </li><li>特別に磁気棒を装備した後、2口丸底フラスコの助けを借りて、窒素雰囲気下に入れてマイクロ波反応のために設計された10ミリリットルバイアル中にすべての化合物を置きます。 </li><li> 1,2-ジクロロエタン（DCE）と脱ガスの溶液7ミリリットルを追加します。 </li><li>金塩粒子を分散させるために2分間、混合物を超音波処理します。 </li><li> 2時間100℃でマイクロ波反応器内の熱。 </li><li>終了したら、丸底フラスコに、粗を転送し、ROTARによって溶媒を除去yの蒸発。 </li><li>移動相としてヘキサンを用いたSiO 2ゲル上のカラムクロマトグラフィーにより粗精製します。 注：Bromocorannulene（4a）は RFでの黄色の固体として得た= 0.38。 99 mgを（収率60％）得られるはずです。未コランニュレン（3A）を回収し、更なる使用のために保存することができます。これは、Rf値= 0.29で表示されます。 </li></ol></li><li> Bomocorannuleneとエチニルトリメチルシランの薗頭カップリング <ol><li> 49 mgの[のPdCl 2（DPPF）]のbromocorannuleneの（0.15ミリモル）、11ミリグラム（0.015ミリモル）49,50（1,1-&#39;bis（diphenylphsphinoあるDPPF）フェロセン、CuIを3mgの（0.015ミリモル）を秤量します。 51 </li><li>磁気棒と一緒に50ミリリットルのシュレンクフラスコにすべての固形物を配置し、窒素雰囲気下に置きます。 </li><li>トリエチルアミン（3 NET）の5.0ミリリットルを加え、混合物を脱気。 </li><li>最後に、エチニルの104μL（0.75ミリモル）を追加します。 </li><li> 2分間混合物を超音波処理金属塩粒子を分散させます。 </li><li>金属塩の付着を防止するため定期的な超音波処理しながら24時間85℃で加熱。 注：混合物の色は、パラジウム（0）の存在を示す、すぐに黒色になりました。 </li><li>室温まで冷却し、 真空中でのNEt 3を蒸発させます。 </li><li> DCM 20ml中の再溶解および5aに対応するRF = 0.28で黄色固体をヘキサンで溶出するシリカゲル上のカラムクロマトグラフィーにより精製します。 41 mgを（収率78％）得られるはずです。 注：粗製物を合理的に純粋な試料が得られるかもしれない、DCM中のセライトパッドで濾過されている場合は、しかし、ホスフィン誘導体は完全に削除されません。 </li></ol></li><li> TMS脱保護によってEthynylcorannuleneの調製 <ol><li> 図5aの35ミリグラム（0.10ミリモル）、無水フッ化カリウムの7.3ミリグラム（0.125ミリモル）を量ります。 </li><li>磁気棒ANを備えた50mlシュレンクフラスコに、全ての固体を配置窒素雰囲気下に置いdは。 </li><li> THFの4ミリリットルとメタノール（MeOH）での4ミリリットルを混合し、シュレンクフラスコ中に混合物を注ぎます。徹底的ドガ。 </li><li>不透明膜で覆うことにより、光から遠ざけフ​​ラスコを保ち、室温で反応することを可能にします。 3.48 ppmのを見て、1 H-NMRで反応を確認してください。出現しなければならない-CCHに対応する信号（ 図3）。 注：この化合物は、反応性であり、容易に分解する末端アルキンを負担するが、我々は、以下に記載のワークアップ中に何の問題も見つかりませんでした。これは自然光の下で行いました。 </li><li>いったん終了し、真空下でTHFを除去し、10mlの水で希釈し、分液漏斗にすべてを転送します。 </li><li> DCMで抽出し（3×15 ml）を、丸底フラスコ内のすべての有機相を結合し、最終的に図6（a）に対応した黄色の固体を得るために、室温で、ロータリーエバポレーターで濃縮しました。 27 mgの（定量的収率）を得なければなりません。 </li></ol></li></ol><img alt="図3" src="/files/ftp_upload/53954/53954fig3.jpg" /> 図 3：1 H-NMRの 5 の スペクトル（500 MHzの、CDCl 3 中 ）（上）と 6（下）-CCH一重が赤い円の中に描かれている。 <a href="https://www.jove.com/files/ftp_upload/53954/53954fig3large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a> クリックケミストリー3.最終組立<ol><li>アスコルビン酸のナトリウム塩の5bの15.3ミリグラム（0.035ミリモル）、6aの20.0ミリグラム（0.073ミリモル）、1.4ミリグラム（0.007ミリモル）のCuSO 4の1.7ミリグラム（0.007ミリモル）・5H 2 Oを秤量</li><li>午前を備えた50mlシュレンクフラスコに、全ての固体を配置agneticバー、窒素雰囲気下に置きます。 </li><li> 3 H 2 O mlのTHF 12 mlと混合し、シュレンクフラスコ中に混合物を注ぎます。溶液を十分に脱気。 </li><li>フラスコの頂部に接続された冷却器を備えた3日間65℃で加熱し、定期的に温度を制御するための反応を確認し、攪拌し、溶媒容量。 1 H-NMRで反応を確認してください。 3.48 ppmのシグナルは消えるはずですし、7.27 ppmのエチニルコランニュレンの消費とトリアゾールユニットの存在を示す（ 図4）にシフトさせること。 </li><li>完了したら、真空下でTHFを除去し、分液漏斗に混合物を移送、水20mlで希釈します。 </li><li> 、DCM（3×20ml）で抽出した丸底フラスコ内のすべての有機相を結合し、ロータリーエバポレーターで濃縮します。 </li><li> Rf値= 0.59で固体淡黄色を与える：ヘキサン/酢酸エチルで溶離するSiO 2ゲル（1：1）でのカラムクロマトグラフィーにより粗精製7に対応します。 27 mgを（収率75％）得られるはずです。 </li></ol><img alt="図4" src="/files/ftp_upload/53954/53954fig4.jpg" /> 図 4：1 H-NMRスペクトル（500 MHzの、CDCl 3 中 ）5bの （上部）、6（ 中央）と 2 日（下） 後に撮影した分量の粗で-CCH信号の消失に注意してください。。 <a href="https://www.jove.com/files/ftp_upload/53954/53954fig4large.jpg" target="_blank">してくださいこの図の拡大版をご覧になるにはこちらをクリックしてください。</a>

The authors have nothing to disclose.

最終化合物7は、非平面の多環芳香族前駆体からの6つのステップ3aと各反応における中等度から非常に良好な収率で3 bの後用意されています。このルートで観察された主な制限は、両方の非平面多環芳香族化合物の臭素化しました。しかしながら、化合物4の場合には、遊離コランニュレンの重要な量は、さらに使用?...

それらの特別な幾何学、コランニュレンとヘリセンが遠い平面から構造を採用し、興味深い特性を生じさせることができる分子であるに。ここ数年では1月15日 、カーボンナノチューブやフラーレンのための分子の受容体の探索は非常に活発な地域であります有機太陽電池、トランジスタ、センサーやその他のデバイス用材料としての可能性アプリケーションに、主に起因16-19。20-28コランニュレンとフラーレンとの間の形状に優れた相補性は設計の目的で、いくつかの研究者の注目を集めています分散力によって超分子会合を確立することができる分子の受容体。29-39 上記非平面の多環芳香族化合物の化学的性質は完全に平面分子について記載したものと同様であるが、所望の選択性および収率を達成するための適切な条件を見出すことが困難な場合がある。40 </sup&gt;本研究では、（7）すべての研究室で見つかった、簡単で一般的な技術を適用することにより、良好な収率でいくつかの手順で3多環芳香族単位を有する分子の合成を提示します。それは溶液中でC 60 37との良好な相互作用を確立するために、ペンチのような構造をとることができるので、分子が非常に重要です。それが原因での立体軸が存在するキラル分子であるヘリセンリンカーに高いキラルフラーレンのおかげでの潜在的な受容体として研究ラインを開くことができます。41-45しかし 、唯一のラセミヘリセンは、この研究で使用されます。 彼らは市販されていないので、この時点では、これらの受容体を合成する唯一の制限は、ヘリセンとcorannulenesの製造です。しかし、新たな方法によれば、彼らは、時間の合理的な短期間に適切な量で得ることができる46-48他の場所で公開されました。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>2,15-Dimethylhexahelicene</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Prepared according to reference 5b,c in the main text.</td>
		</tr>
		<tr>
			<td>Corannulene</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Prepared according to reference 5a in the main text.</td>
		</tr>
		<tr>
			<td>N-Bromosuccinimide (NBS)</td>
			<td>Sigma Aldrich</td>
			<td>B8.125-5</td>
			<td>ReagentPlus&#174;, 99%. Recrystallized from hot water.</td>
		</tr>
		<tr>
			<td>Benzoyl peroxide (BPO)</td>
			<td>Sigma Aldrich</td>
			<td>B-2030</td>
			<td>~70% (titration). 30% water as stabilizer.</td>
		</tr>
		<tr>
			<td>Sodium azide</td>
			<td>Sigma Aldrich</td>
			<td>S2002</td>
			<td>ReagentPlus&#174;, &#8805;99.5%.</td>
		</tr>
		<tr>
			<td>Gold (III) chloride Hydrate</td>
			<td>Sigma Aldrich</td>
			<td>50778</td>
			<td>puriss. p.a., ACS reagent, &#8805;49% Au basis.</td>
		</tr>
		<tr>
			<td>Ethynyltrimethylsilane</td>
			<td>Sigma Aldrich</td>
			<td>218170</td>
			<td>98%.</td>
		</tr>
		<tr>
			<td>[PdCl2(dppf)]</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Prepared according to reference 6 in the main text.</td>
		</tr>
		<tr>
			<td>CuI</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Prepared according to reference 7 in the main text.</td>
		</tr>
		<tr>
			<td>KF</td>
			<td>Sigma Aldrich</td>
			<td>307599</td>
			<td>99%, spray-dried.</td>
		</tr>
		<tr>
			<td>(+)-Sodium L-ascorbate</td>
			<td>Fluka</td>
			<td>11140</td>
			<td>BioXtra, &#8805;99.0% (NT).</td>
		</tr>
		<tr>
			<td>Copper(II) Sulphate 5-hydrate</td>
			<td>Panreac</td>
			<td>131270</td>
			<td>for analysis.</td>
		</tr>
		<tr>
			<td>Carbon tetrachloride (CCl4)</td>
			<td>Fluka</td>
			<td>87030</td>
			<td>for IR spectroscopy, &#8805;99.9%.</td>
		</tr>
		<tr>
			<td>Dichloromethane (DCM)</td>
			<td>Fisher Scientific</td>
			<td>D/1852/25</td>
			<td>Analytical reagent grade. Distilled prior to use.</td>
		</tr>
		<tr>
			<td>Hexane</td>
			<td>Fisher Scientific</td>
			<td>H/0355/25</td>
			<td>Analytical reagent grade. Distilled prior to use.</td>
		</tr>
		<tr>
			<td>Ethyl acetate</td>
			<td>Scharlau</td>
			<td>AC0145025S</td>
			<td>Reagent grade. Distilled prior to use.</td>
		</tr>
		<tr>
			<td>Tetrahydrofuran (THF)</td>
			<td>Fisher Scientific</td>
			<td>T/0701/25</td>
			<td>Analytical reagent grade. Distilled prior to use.</td>
		</tr>
		<tr>
			<td>1,2-Dichloroethane (DCE)</td>
			<td>Sigma Aldrich</td>
			<td>D6,156-3</td>
			<td>ReagentPlus&#174;, 99%.</td>
		</tr>
		<tr>
			<td>Methanol (MeOH)</td>
			<td>VWR</td>
			<td>20847.36</td>
			<td>AnalaR NORMAPUR.</td>
		</tr>
		<tr>
			<td>Triethyl amine (NEt3)</td>
			<td>Sigma Aldrich</td>
			<td>T0886</td>
			<td>&#8805;99%.</td>
		</tr>
		<tr>
			<td>Silica gel</td>
			<td>Acros</td>
			<td>360050010</td>
			<td>Particle size 40-60mm.</td>
		</tr>
		<tr>
			<td>Sand - low iron</td>
			<td>Fisher Scientific</td>
			<td>S/0360/63</td>
			<td>General purpose grade.</td>
		</tr>
		<tr>
			<td>TLC Silica gel 60 F254</td>
			<td>Merck</td>
			<td>1.05554.0001</td>
			<td></td>
		</tr>
		<tr>
			<td>Monowave 300 (Microwave reactor)</td>
			<td>Anton Para</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sonicator</td>
			<td>Grupo Selecta</td>
			<td>3000513</td>
			<td>6 Litres.</td>
		</tr>
	</tbody>
</table>

preparation of a corannulene-functionalized hexahelicene by copper(i)-catalyzed alkyne-azide cycloaddition of nonplanar polyaromatic units

The main purpose of this video is to show 6 reaction steps of a convergent synthesis and prepare a complex molecule containing up to three nonplanar polyaromatic units, which are two corannulene moieties and a racemic hexahelicene linking them. The compound described in this work is a good host for fullerenes. Several common organic reactions, such as free-radical reactions, C-C coupling or click chemistry, are employed demonstrating the versatility of functionalization that this compound can accept. All of these reactions work for planar aromatic molecules. With subtle modifications, it is possible to achieve similar results for nonplanar polyaromatic compounds.

コランニュレン（3 a）と2,15-dimethylhexahelicene（ 図3b） は、非常に良好な収率（ 図5）との直接的なやり方で現在の方法46-48以下調製することができます。両方の最終的な分子の収束合成の発散を生じる、出発物質として、一般的な分子、2,7-ジメチルナフタレンを共有します。 <p class...

Watch this Scientific Journal Video about Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units at JoVE.com

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

ここでは、合理的な収率で容易に組み立てる3非平面多環芳香族単位から構成される複雑な有機化合物を合成するためのプロトコルを提示します。

銅（I）によるコランニュレン官能Hexaheliceneの調製は、非平面多環芳香族ユニットのアルキンアジド付加環を - 触媒

The main purpose of this video is to show 6 reaction steps of a convergent synthesis and prepare a complex molecule containing up to three nonplanar ...

preparation-corannulene-functionalized-hexahelicene-copper-i

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Unit 1

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Aromatic Compounds

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11.4K ビュー.  Universidad de Valladolid. ここでは、合理的な収率で容易に組み立てる3非平面多環芳香族単位から構成される複雑な有機化合物を合成するためのプロトコルを提示します。 

ビデオ: Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

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

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of molecular iodine to samarium metal in THF.1,2-3 It is a mild and selective single electron reductant and its versatility is a result of its ability to initiate a wide range of reductions including C-C bond-forming and cascade or sequential reactions. SmI2 can reduce a variety of functional groups including sulfoxides and sulfones, phosphine oxides, epoxides, alkyl and aryl halides, carbonyls, and conjugated double bonds.2-12 One of the fascinating features of SmI-2-mediated reactions is the ability to manipulate the outcome of reactions through the selective use of cosolvents or additives. In most instances, additives are essential in controlling the rate of reduction and the chemo- or stereoselectivity of reactions.13-14 Additives commonly utilized to fine tune the reactivity of SmI2 can be classified into three major groups: (1) Lewis bases (HMPA, other electron-donor ligands, chelating ethers, etc.), (2) proton sources (alcohols, water etc.), and (3) inorganic additives (Ni(acac)2, FeCl3, etc).3
Understanding the mechanism of SmI2 reactions and the role of the additives enables utilization of the full potential of the reagent in organic synthesis. The Sm-Barbier reaction is chosen to illustrate the synthetic importance and mechanistic role of two common additives: HMPA and Ni(II) in this reaction. The Sm-Barbier reaction is similar to the traditional Grignard reaction with the only difference being that the alkyl halide, carbonyl, and Sm reductant are mixed simultaneously in one pot.1,15 Examples of Sm-mediated Barbier reactions with a range of coupling partners have been reported,1,3,7,10,12 and have been utilized in key steps of the synthesis of large natural products.16,17 Previous studies on the effect of additives on SmI2 reactions have shown that HMPA enhances the reduction potential of SmI2 by coordinating to the samarium metal center, producing a more powerful,13-14,18 sterically encumbered reductant19-21 and in some cases playing an integral role in post electron-transfer steps facilitating subsequent bond-forming events.22 In the Sm-Barbier reaction, HMPA has been shown to additionally activate the alkyl halide by forming a complex in a pre-equilibrium step.23
Ni(II) salts are a catalytic additive used frequently in Sm-mediated transformations.24-27 Though critical for success, the mechanistic role of Ni(II) was not known in these reactions. Recently it has been shown that SmI2 reduces Ni(II) to Ni(0), and the reaction is then carried out through organometallic Ni(0) chemistry.28
These mechanistic studies highlight that although the same Barbier product is obtained, the use of different additives in the SmI2 reaction drastically alters the mechanistic pathway of the reaction. The protocol for running these SmI2-initiated reactions is described.

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

A straightforward procedure for the preparation of samarium diiodide (SmI2) in THF is described. The role of two main additives namely hexamethylphosphoramide (HMPA) and Ni(acac)2 in Sm mediated reactions is demonstrated in the Sm-Barbier reaction.

二ヨウ化サマリウム（SMIの調製および使用<sub&gt; 2</sub&gt;）有機合成における：サマリウムバルビエ反応におけるHMPAとNi（II）塩の力学的役割

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

化学

Isolation and Preparation of Bacterial Cell Walls for Compositional Analysis by Ultra Performance Liquid Chromatography

The bacterial cell wall is critical for the determination of cell shape during growth and division, and maintains the mechanical integrity of cells in the face of turgor pressures several atmospheres in magnitude. Across the diverse shapes and sizes of the bacterial kingdom, the cell wall is composed of peptidoglycan, a macromolecular network of sugar strands crosslinked by short peptides. Peptidoglycan&#8217;s central importance to bacterial physiology underlies its use as an antibiotic target and has motivated genetic, structural, and cell biological studies of how it is robustly assembled during growth and division. Nonetheless, extensive investigations are still required to fully characterize the key enzymatic activities in peptidoglycan synthesis and the chemical composition of bacterial cell walls. High Performance Liquid Chromatography (HPLC) is a powerful analytical method for quantifying differences in the chemical composition of the walls of bacteria grown under a variety of environmental and genetic conditions, but its throughput is often limited. Here, we present a straightforward procedure for the isolation and preparation of bacterial cell walls for biological analyses of peptidoglycan via HPLC and Ultra Performance Liquid Chromatography (UPLC), an extension of HPLC that utilizes pumps to deliver ultra-high pressures of up to 15,000 psi, compared with 6,000 psi for HPLC. In combination with the preparation of bacterial cell walls presented here, the low-volume sample injectors, detectors with high sampling rates, smaller sample volumes, and shorter run times of UPLC will enable high resolution and throughput for novel discoveries of peptidoglycan composition and fundamental bacterial cell biology in most biological laboratories with access to an ultracentrifuge and UPLC.

The bacterial cell wall is composed of peptidoglycan, a macromolecular network of sugar strands crosslinked by peptides. Ultra Performance Liquid Chromatography provides high resolution and throughput for novel discoveries of peptidoglycan composition. We present a procedure for the isolation of cell walls (sacculi) and their subsequent preparation for analysis via UPLC.

超高性能液体クロマトグラフィーによる組成解析のための細菌細胞壁の分離と調製

The bacterial cell wall is critical for the determination of cell shape during growth and division, and maintains the mechanical integrity of cells in the ...

Real-time Monitoring of Reactions Performed Using Continuous-flow Processing: The Preparation of 3-Acetylcoumarin as an Example

By using inline monitoring, it is possible to optimize reactions performed using continuous-flow processing in a simple and rapid way. It is also possible to ensure consistent product quality over time using this technique. We here show how to interface a commercially available flow unit with a Raman spectrometer. The Raman flow cell is placed after the back-pressure regulator, meaning that it can be operated at atmospheric pressure. In addition, the fact that the product stream passes through a length of tubing before entering the flow cell means that the material is at RT. It is important that the spectra are acquired under isothermal conditions since Raman signal intensity is temperature dependent. Having assembled the apparatus, we then show how to monitor a chemical reaction, the piperidine-catalyzed synthesis of 3-acetylcoumarin from salicylaldehyde and ethyl acetoacetate being used as an example. The reaction can be performed over a range of flow rates and temperatures, the in-situ monitoring tool being used to optimize conditions simply and easily.

Real-time monitoring allows for fast optimization of reactions performed using continuous-flow processing. Here the preparation of 3-acetylcoumarin is used as an example. The apparatus for performing in-situ Raman monitoring is described, as are the steps required to optimize the reaction.

連続フロー処理を​​使用して行われる反応のリアルタイムモニタリング：例として3- Acetylcoumarinの調製

By using inline monitoring, it is possible to optimize reactions performed using continuous-flow processing in a simple and rapid way. It is also possible ...

Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles

Amphiphilic block copolymers like polyethyleneglycol-block-polylactic acid (PEG-b-PLA) can self-assemble into micelles above their critical micellar concentration forming hydrophobic cores surrounded by hydrophilic shells in aqueous environments. The core of these micelles can be utilized to load hydrophobic, poorly water soluble drugs like docetaxel (DTX) and everolimus (EVR). Systematic characterization of the micelle structure and drug loading capabilities are important before in vitro and in vivo studies can be conducted. The goal of the protocol described herein is to provide the necessary characterization steps to achieve standardized micellar products. DTX and EVR have intrinsic solubilities of 1.9 and 9.6 &#181;g/ml respectively Preparation of these micelles can be achieved through solvent casting which increases the aqueous solubility of DTX and EVR to 1.86 and 1.85 mg/ml, respectively. Drug stability in micelles evaluated at room temperature over 48 hr indicates that 97% or more of the drugs are retained in solution. Micelle size was assessed using dynamic light scattering and indicated that the size of these micelles was below 50 nm and depended on the molecular weight of the polymer. Drug release from the micelles was assessed using dialysis under sink conditions at pH 7.4 at 37 oC over 48 hr. Curve fitting results indicate that drug release is driven by a first order process indicating that it is diffusion driven.

The goal of this protocol is to describe the preparation and characterization of physically entrapped, poorly water soluble drugs in micellar drug delivery systems composed of amphiphilic block copolymers.

調製とキャラクタリゼーション個々のとマルチ薬ロード物理的に捕捉さ高分子ミセル

Amphiphilic block copolymers like polyethyleneglycol-block-polylactic acid (PEG-b-PLA) can self-assemble into micelles above their critical micellar ...

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G&#39; bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

カーボンナノチューブにより安定化内部自己組織化脂質粒子の簡便な調製

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled ...

Preparation of Macroporous Epitaxial Quartz Films on Silicon by Chemical Solution Deposition

This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step process based on the preparation of a sol in a one-pot synthesis which is followed by the deposition of a gel film on Si(100) substrates by evaporation induced self-assembly using the dip-coating technique and ends with a thermal treatment of the material to induce the gel crystallization and the growth of the quartz film. The formation of a silica gel is based on the reaction of a tetraethyl orthosilicate and water, catalyzed by HCl, in ethanol. However, the solution contains two additional components that are essential for preparing mesoporous epitaxial quartz films from these silica gels dip-coated on Si. Alkaline earth ions, like Sr2+ act as glass melting agents that facilitate the crystallization of silica and in combination with cetyl trimethylammonium bromide (CTAB) amphiphilic template form a phase separation responsible of the macroporosity of the films. The good matching between the quartz and silicon cell parameters is also essential in the stabilization of quartz over other SiO2 polymorphs and is at the origin of the epitaxial growth.

A protocol is presented for the preparation of piezoelectric macroporous epitaxial films of quartz on silicon by solution chemistry using dip-coating and thermal treatments in air.

化学溶液法によるシリコン上のマクロポーラスエピタキシャル石英薄膜の作製

This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step ...

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by &#960;-&#960; Stacking Interactions

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE). Characterization of the copolymer revealed a narrow molecular distribution (PDI &#60; 1.03) and confirmed the degree of polymerization of mPEG122-b-(PheGE)15. The critical micelle concentration of the copolymer was evaluated using an established fluorescence method with the aggregation behavior evaluated by dynamic light scattering and transmission electronic microscopy. The potential of the copolymer for use in drug delivery applications was evaluated in a preliminary manner including in vitro biocompatibility, loading and release of the hydrophobic anti-cancer drug doxorubicin (DOX). A stable micelle formulation of DOX was prepared with drug loading levels up to 14% (wt%), drug loading efficiencies &#62; 60% (w/w) and sustained release of drug over 4 days under physiologically relevant conditions (acidic and neutral pH, presence of albumin). The high drug loading level and sustained release is attributed to stabilizing &#960;-&#960; interactions between DOX and the core-forming block of the micelles.

The key steps of living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE) are described. The resulting block copolymer micelles (BCMs) were loaded with doxorubicin 14% (wt%) and sustained release of drug over 4 days under physiologically relevant conditions was obtained.

π-πスタッキング相互作用によって安定化されたブロック共重合体ミセルの調製のための両親媒性共重合体のアニオン重合

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl ...

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)

We present herein the optimized synthesis of a triphosphenium bromide salt. Apart from being a versatile metathesis reagent, this unusually stable low-valent-phosphorus-containing compound acts as a useful P+ transfer agent. Unlike traditional methods employed to access low-coordinate phosphorus species which usually require pyrophoric phosphorus-containing precursors (white phosphorus, Tris(trimethylsilyl)phosphine, etc.), or harsh reducing agents (alkali metals, potassium graphite, etc.), the current approach does not involve pyrophoric or explosive reagents and can be done on large scales (&#62;20 g) in excellent yields by undergraduates with basic air-free synthetic training. The bromide counter ion is readily exchanged with other anions such as tetraphenyl borate (described herein) using typical salt metathesis reagents to obtain materials with desired properties and reactivities. The versatility of this P+ transfer approach is exemplified by the reactions of these triphosphenium precursors with an N-heterocyclic carbene and an anionic bisphosphine, each of which readily displace the neutral bisphosphine to give an NHC-stabilized phosphorus(I) cation and a phosphorus(I) containing zwitterion, respectively.

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI

The synthesis of a triphosphenium bromide salt is described and its use as a P+ transfer agent is outlined by reactions with an N-heterocyclic carbene and an anionic bisphosphine, yielding an NHC-stabilized P(I) cation and a P(I) containing zwitterion, respectively.

Triphosphenium臭化物塩の調製と反応性：リンの便利で安定したソース（I）

We present herein the optimized synthesis of a triphosphenium bromide salt. Apart from being a versatile metathesis reagent, this unusually stable ...

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry

Pre-targeting combined with bioorthogonal chemistry is emerging as an effective way to create new radiopharmaceuticals. Of the methods available, the inverse electron demand Diels-Alder (IEDDA) cycloaddition between a radiolabeled tetrazines and trans-cyclooctene (TCO) linked to a biomolecule has proven to be a highly effective bioorthogonal approach to imaging specific biological targets. Despite the fact that technetium-99m remains the most widely used isotope in diagnostic nuclear medicine, there is a scarcity of methods for preparing 99mTc-labeled tetrazines. Herein we report the preparation of a family of tridentate-chelate-tetrazine derivatives and their Tc(I) complexes. These hitherto unknown compounds were radiolabeled with 99mTc using a microwave-assisted method in 31% to 83% radiochemical yield. The products are stable in saline and PBS and react rapidly with TCO derivatives in vitro. Their in vivo pre-targeting abilities were demonstrated using a TCO-bisphosphonate (TCO-BP) derivative that localizes to regions of active bone metabolism or injury. In murine studies, the 99mTc-tetrazines showed high activity concentrations in knees and shoulder joints, which was not observed when experiments were performed in the absence of TCO-BP. The overall uptake in non-target organs and pharmacokinetics varied greatly depending on the nature of the linker and polarity of the chelate.

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry

Here, we describe a protocol for radiolabeling and in vivo testing of tridentate 99mTc(I) chelate-tetrazine derivatives for pre-targeting and bioorthogonal chemistry.

の調製と評価<sup&gt; 99メートル</sup&gt; Tc標識三座キレートバイオ直交化学反応を用いて事前ターゲティングするため

Pre-targeting combined with bioorthogonal chemistry is emerging as an effective way to create new radiopharmaceuticals. Of the methods available, the ...

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.

貴重なリガンドにアクセスすると、遷移金属のためのサポート：1,2,3,4,5-ペンタメチルシクロペンタジエンの変形、中間規模の調製

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

銅（I）によるコランニュレン官能Hexaheliceneの調製は、非平面多環芳香族ユニットのアルキンアジド付加環を - 触媒

要約

さらに動画を探す

この動画の章

二ヨウ化サマリウム（SMIの調製および使用

超高性能液体クロマトグラフィーによる組成解析のための細菌細胞壁の分離と調製

連続フロー処理を使用して行われる反応のリアルタイムモニタリング：例として3- Acetylcoumarinの調製

調製とキャラクタリゼーション個々のとマルチ薬ロード物理的に捕捉さ高分子ミセル

カーボンナノチューブにより安定化内部自己組織化脂質粒子の簡便な調製

化学溶液法によるシリコン上のマクロポーラスエピタキシャル石英薄膜の作製

π-πスタッキング相互作用によって安定化されたブロック共重合体ミセルの調製のための両親媒性共重合体のアニオン重合

Triphosphenium臭化物塩の調製と反応性：リンの便利で安定したソース（I）

の調製と評価

貴重なリガンドにアクセスすると、遷移金属のためのサポート：1,2,3,4,5-ペンタメチルシクロペンタジエンの変形、中間規模の調製

銅（I）によるコランニュレン官能Hexaheliceneの調製は、非平面多環芳香族ユニットのアルキンアジド付加環を - 触媒

要約

さらに動画を探す

この動画の章

二ヨウ化サマリウム（SMIの調製および使用

超高性能液体クロマトグラフィーによる組成解析のための細菌細胞壁の分離と調製

連続フロー処理を​​使用して行われる反応のリアルタイムモニタリング：例として3- Acetylcoumarinの調製

調製とキャラクタリゼーション個々のとマルチ薬ロード物理的に捕捉さ高分子ミセル

カーボンナノチューブにより安定化内部自己組織化脂質粒子の簡便な調製

化学溶液法によるシリコン上のマクロポーラスエピタキシャル石英薄膜の作製

π-πスタッキング相互作用によって安定化されたブロック共重合体ミセルの調製のための両親媒性共重合体のアニオン重合

Triphosphenium臭化物塩の調製と反応性：リンの便利で安定したソース（I）

の調製と評価

貴重なリガンドにアクセスすると、遷移金属のためのサポート：1,2,3,4,5-ペンタメチルシクロペンタジエンの変形、中間規模の調製

連続フロー処理を使用して行われる反応のリアルタイムモニタリング：例として3- Acetylcoumarinの調製