This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. We thank the University of North Carolina Wilmington for providing the seawater.

1.合成1,4-ベンゼンビス（iminoguanidinium）塩化物（BBIG-CL） <ol><li> その場 1,4-ベンゼンビス（iminoguanidinium）塩化物リガンド（BBIG-CL）の合成と硫酸とのその結晶化で <ol><li>磁気撹拌棒を備えた25ml丸底フラスコに0.067テレフタルアルデヒドのグラムおよび脱イオン水10mlにaminoguanidinium塩化0.5 M水溶液2.2 mLを加え。 </li><li> 20℃で4時間磁気溶液を攪拌します。これはBBIG-Clをわずかに黄色の溶液が得られます。 </li><li>硫酸ナトリウムの1 M水溶液0.5ミリリットルを追加します。これは、結晶性の白色固体としてBBIG-SO 4の瞬間降水量になります。 </li><li> BBIG-SO 4を回復するための固体使用して真空ろ過をフィルタリングします。純粋な硫酸塩を得るために、水5mlアリコートで濾紙上の固体を5回洗浄します。 </li><li>結晶BBIG-SOの相純度をチェック<sub&gt;図4は、粉末X線回折12によって得られました。 図1に示すパターンと比較してください。 </li></ol></li><li> 1,4-ベンゼンビスの域外合成（iminoguanidinium）塩化11 <ol><li>磁気撹拌棒を備えた50mlの丸底フラスコ中のエタノール20mlにテレフタルアルデヒドを4gとaminoguanidiniumクロライド7.26グラム加えます。 </li><li>ホットプレートを用いて60℃に溶液を加熱し、そして2時間、磁気撹拌棒で撹拌しました。 20°Cにソリューションを冷却し、それが濾紙装備したブフナー漏斗を通して真空濾過により固体を収集した後、3時間放置します。 </li><li>沸騰するまでホットプレート上でエタノールと熱の20ミリリットルで得られた固体を一時停止します。固体は、この時点で溶液中に完全に入らない場合、すべての固体が溶解するまで、溶液を沸騰温度に到達するたびに、許可、エタノールの少量のアリコート（1 ml）を加えます。 </li><li>フラスコを室温temperatuに冷却することを許可します再、一​​晩0℃の冷凍庫に入れます。真空濾過を用いてブフナー漏斗装備濾紙を通して濾過することにより固体を収集します。 </li><li> 1 H NMR分光法13によってBBIG-Clでのアイデンティティおよび純度を確認してください。 図2に示されるスペクトルと比較してください。 </li></ol></li></ol>海水から2硫酸の分離<ol><li> BBIG-SO 4などの硫酸塩の結晶化 注：硫酸を除去するために必要なBBIG-Clでの量は、海水中の硫酸の正確な量に依存します。これは、硫酸の99％の除去中の硫酸結果にBBIG-Clでの相対的な1.5当量を使用していることがわかりました。 BaCl 2を用いた滴定により決定されるように、このプロトコルで使用される海水は、30 mMの硫酸濃度を有します。 <ol><li>浮遊粒子とバイオ生物を除去するための小孔径が0.22μmのシリンジフィルターや濾過膜で海水をフィルタリングします。 </li><li> 30を作ります前のセクションで説明したように調製し、脱イオン水と固体BBIG-Clで使用BBIG-ClをmM溶液。 </li><li> 1（v / v）の割合：1.5で海水にBBIG-Cl溶液を追加します。 </li><li>硫酸の定量的（&gt; 99％）除去を確実にするために数時間のために、混合液を撹拌しました。 </li><li>真空濾過を用いてブフナー漏斗装備濾紙を通して濾過することにより固体を収集します。水5mlアリコートで濾紙上の固体を5回洗浄します。 </li><li>真空下で単離された固体を乾燥し、収量を決定するために、それを量ります。 </li></ol></li><li>リガンド回復<ol><li>磁気撹拌棒を備えた20ミリリットルのシンチレーションバイアル中のNaOH（10％）の2ミリリットルの溶液にBBIG-SO 4の53.1 mgを追加します。 </li><li> 20℃で2時間混合物を撹拌しました。わずかに黄色の沈殿物が形成されます。 </li><li>真空濾過を使用して濾紙装備したブフナー漏斗を通して固体をフィルタリングします。 0.2を用いて濾紙上の固体を洗浄mlの水、そして真空下で乾燥しました。 </li><li>ビス（グアニジン）、遊離塩基としての同一性を確認するために、NMR 13で回収した固体を特徴づけます。 図3に示すNMRスペクトルと比較してください。 </li></ol></li><li>液体シンチレーション計数をβによって海水から削除硫酸塩の量の決意 注意：この手法は、通常、ほとんどの研究室で発生したものよりも危険性の異なるクラスをもたらす放射性同位元素の使用を含みます。放射性核種を取り扱う場合には、特別な放射線防護装置が通常必要とされます。したがって、手順​​に従って慎重に作業していること、および安全管理者が助言・指導のために参照されることが不可欠です。 <ol><li>硫黄-35放射性同位元素（5 mCiの/ミリリットル）のストック溶液の量は、以下の式（CPMとキュリー（Ciのを使用して、海水溶液1ミリリットル当たり毎分500万人以上のカウント（CPM）が存在することを確認するために使用される計算）メジャーfの両方の単位であり、または放射能）： <img alt="式（1）" src="/files/ftp_upload/54411/54411eq1.jpg" /> <img alt="式（2）" src="/files/ftp_upload/54411/54411eq2.jpg" /> <img alt="式3" src="/files/ftp_upload/54411/54411eq3.jpg" /></li><li> 35 S放射性標識された硫酸ナトリウム溶液の5.0 mCiの/ ml溶液の0.0112 mlの海水25mlのスパイク。 </li><li>調製0、15、30、33、45、及び脱イオン水中BBIG-Clを60mMの溶液と35 S-放射標識硫酸等量のこれらの溶液の0.750ミリリットル組み合わせを2mlの遠心管に海水をスパイクしました。 </li><li> 24時間25±0.2℃の一定温度に維持したインキュベーター/エアボックス内の回転ホイールまたは渦を経由して、混合液を撹拌しました。 </li><li> 25℃で10分間、1500×gでソリューションを遠心。 </li><li>遠心分離後、シリンジを用いて各溶液を1.2mlのを削除し、懸濁除去するために0.22μmのシリンジフィルターを介してフィルター<html>沈殿します。ピペットポリプロピレンシンチレーションバイアル中のシンチレーションカクテル20ml中にこれらの溶液をそれぞれ1.0 mlです。何BBIG-Clで（対照溶液）を含有しない溶液は、従来のシンチレーションカクテルに添加し、脱イオン水で10倍に希釈されるべきです。 </li><li>サンプルおよび液体シンチレーションカウンターでのシンチレーションカクテルを含むシンチレーションバイアルを置き、前暗適応にサンプルを可能にするために、カウントに1時間放置します。 注：サンプルをカウントする前に、機器を較正し、各試料を30分間カウントすることを可能にします。溶液中の硫酸の濃度を決定する際に使用されるバックグラウンド補正を可能にするために、唯一のシンチレーションカクテルを含む追加のバイアルを数えます。 </li><li>以下の式を使用して、削除硫酸塩の量を決定します。 <img alt="式4" src="/files/ftp_upload/54411/54411eq4.jpg" /> 54411 / 54411eq5.jpg &quot;/&gt; <img alt="式6" src="/files/ftp_upload/54411/54411eq6.jpg" /></li></ol></li></ol>

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The authors have nothing to disclose.

この技術は、非常に堅牢に書かれた手順から多くの逸脱にかなり寛容です。従わなければならないしかし、2つの重要なステップがあります。まず、BBIG-Clでリガンドは、できるだけ純粋である必要があります。不純物は結晶化し、得られた硫酸塩の溶解性には影響しませんが、またそれが困難な溶液からの定量的な硫酸塩の除去に必要な量を計算することになります。この技術は微妙な変化?...

競争力のある水溶液から親水性オキソアニオンを選択的に分離（ 例えば 、硫酸、クロム酸塩、リン酸塩）は環境改善、エネルギー生産、およびヒトの健康との関連での基本的な課題である。特に1,2硫酸塩は、そのように水から抽出することが困難ですその水和球を当てると極性の低い環境に移行するための固有不本意。3、より効率的な水性硫酸抽出の作成 ​​は、典型的には、しばしば毒性試薬および溶媒を含む、合成および精製が困難と退屈な複雑な受容体を必要とします。4,5 選択的結晶化は、水からの分離を硫酸するシンプルで効果的な代替手段を提供しています。6-9などのBa 2+、Pbの2+、またはRaが2+形非常に不溶性の硫酸塩のようないくつかの金属陽イオンは、硫酸塩分離におけるそれらの使用は必ずしも実用的ではありませんがその高いtoxiへ都市と時々-低い選択。硫酸塩沈殿剤として有機配位子を採用することにより、有機分子に特徴的なデザインする構造の多様性と従順を利用しています。水性硫酸塩結晶化のための理想的な有機配位子は、水に可溶で、まだ比較的短時間でかつ競合するイオンの高濃度の存在下で不溶性の硫酸塩または錯体を形成すべきです。さらに、合成とリサイクルが容易であるべきです。そのようなリガンド、1,4-ベンゼンビス（iminoguanidinium）（BBIG）、自己集合し、その場に 2つの市販の前駆体、テレフタルアルデヒド及びaminoguanidiniumクロリドから、最近、水性硫酸分離において非常に有効であることが見出された。10リガンド水溶性の塩化物の形態であり、選択的に簡単な濾過によって溶液から除去することができる非常に不溶性の塩に硫酸結晶化します。 BBIGリガンドは次いで、脱プロトン化することによって回収することができますqueous NaOHおよびHCl水溶液でバック塩化物形態に変換され、別の分離サイクルで再利用することができる中性ビスiminoguanidineの結晶。水から硫酸塩を除去する際に、このリガンドの有効性は、溶液中に残存する硫酸濃度を監視する陰イオンの微量の正確な測定を可能にし、より高度な技術を必要とする、もはや単純な作業であることがとても素晴らしいです。この目的のために、β液体シンチレーション計数と一緒に35 S放射性標識硫酸トレーサーは、一般に、液-液抽出分離に利用技術を用いて、最近硫酸塩の結晶化をモニタリングするのに有効であることが実証された。8 このプロトコルは、水溶液から硫酸塩としてBBIGリガンドおよびその結晶のその場合成にワンポットを示しています。リガンド11の域外合成はまた、共同として提示されています使用する準備ができるまで結晶形で保存することができるBBIG-Clを、より多量の生産のためのnvenient方法。先に調製したBBIG-Clをリガンドを使用して、海水からの硫酸除去がその後実証されています。最後に、35 Sで標識された硫酸塩と海水中の硫酸濃度を測定するβ液体シンチレーションカウンターの使用が実証されます。このプロトコルは、水性陰イオン分離のための選択的結晶化の使用を模索中で広く興味のある人のためのチュートリアルを提供することを意図しています。

<table><tbody><tr><td>Terephthalaldehyde</td><td>Sigma</td><td>T2207</td><td></td></tr><tr><td>Aminoguanidinium Chloride</td><td>Sigma</td><td>#396494</td><td></td></tr><tr><td>Sodium Sulfate</td><td>Sigma</td><td>#239313</td><td></td></tr><tr><td>Barium Chloride</td><td>Sigma</td><td>#342920</td><td>Highly Toxic</td></tr><tr><td>Ethanol</td><td>Any</td><td></td><td>Reagent Grade (190 proof)</td></tr><tr><td>Sodium Hydroxide</td><td>EMD</td><td>SX0590-1</td><td></td></tr><tr><td>Hydrochloric Acid</td><td>Sigma</td><td>#258148</td><td></td></tr><tr><td>Filter Paper</td><td>Any</td><td>-</td><td>Any qualitative or analytical filter paper will work</td></tr><tr><td>Syringe Filter (0.22 &amp;#956;m)</td><td>Any</td><td>-</td><td>Nylon filter</td></tr><tr><td>&lt;sup&gt;35&lt;/sup&gt;S Labeled Sulfate</td><td>Perkin Elmer</td><td>NEX041005MC</td><td></td></tr><tr><td>Ultima Gold Scintillation Cocktail</td><td>Perkin Elmer</td><td>#6013329</td><td></td></tr><tr><td>Polypropylene Vials&amp;nbsp;</td><td>Any</td><td>-</td><td></td></tr><tr><td>Disposable Syringe (2-3 ml)</td><td>Any</td><td>-</td><td>Any disposable plastic syringe works</td></tr></tbody></table>

sulfate separation by selective crystallization with a bis-iminoguanidinium ligand

A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand is synthesized as the chloride salt (BBIG-Cl) by in situ imine condensation of terephthalaldehyde with aminoguanidinium chloride in water, followed by crystallization as the sulfate salt (BBIG-SO4). Alternatively, BBIG-Cl is synthesized ex situ in larger scale from ethanol. The sulfate separation ability of the BBIG ligand is demonstrated by selective and quantitative crystallization of sulfate from seawater. The ligand can be recycled by neutralization of BBIG-SO4 with aqueous NaOH and crystallization of the neutral bis-iminoguanidine, which can be converted back into BBIG-Cl with aqueous HCl and reused in another separation cycle. Finally, 35S-labeled sulfate and &#946; liquid scintillation counting are employed for monitoring the sulfate concentration in solution. Overall, this protocol will instruct the user in the necessary skills to synthesize a ligand, employ it in the selective crystallization of sulfate from aqueous solutions, and quantify the separation efficiency.

BBIG-SO 4（ 図1）の粉末X線回折パターンは、結晶化固体の同一性の明確な確認を可能にします。参照1対得られたパターンを比較することで、ピーク強度は、以下のピークの位置よりも重要。基準に示されているすべての強いピークが得られた試​​料中に存在しなければなりません。基準パターンには存在しないサンプル中の強いピークの出現は?...

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Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand

ビス（iminoguanidinium）リガンドおよび硫酸の選択的分離におけるその利用をその場水系合成のためのプロトコルが提示されています。

ビスiminoguanidiniumリガンドと選択的結晶化により硫酸の分離

A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, ...

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8.3K ビュー.  Oak Ridge National Laboratory. ビス（iminoguanidinium）リガンドおよび硫酸の選択的分離におけるその利用をその場水系合成のためのプロトコルが提示されています。 

ビデオ: Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand

Synthesis and Purification of Iodoaziridines Involving Quantitative Selection of the Optimal Stationary Phase for Chromatography

The highly diastereoselective preparation of cis-N-Ts-iodoaziridines through reaction of diiodomethyllithium with N-Ts aldimines is described. Diiodomethyllithium is prepared by the deprotonation of diiodomethane with LiHMDS, in a THF/diethyl ether mixture, at -78 &#176;C in the dark. These conditions are essential for the stability of the LiCHI2 reagent generated. The subsequent dropwise addition of N-Ts aldimines to the preformed diiodomethyllithium solution affords an amino-diiodide intermediate, which is not isolated. Rapid warming of the reaction mixture to 0 &#176;C promotes cyclization to afford iodoaziridines with exclusive cis-diastereoselectivity. The addition and cyclization stages of the reaction are mediated in one reaction flask by careful temperature control.
Due to the sensitivity of the iodoaziridines to purification, assessment of suitable methods of purification is required. A protocol to assess the stability of sensitive compounds to stationary phases for column chromatography is described. This method is suitable to apply to new iodoaziridines, or other potentially sensitive novel compounds. Consequently this method may find application in range of synthetic projects. The procedure involves firstly the assessment of the reaction yield, prior to purification, by 1H NMR spectroscopy with comparison to an internal standard. Portions of impure product mixture are then exposed to slurries of various stationary phases appropriate for chromatography, in a solvent system suitable as the eluent in flash chromatography. After stirring for 30 min to mimic chromatography, followed by filtering, the samples are analyzed by 1H NMR spectroscopy. Calculated yields for each stationary phase are then compared to that initially obtained from the crude reaction mixture. The results obtained provide a quantitative assessment of the stability of the compound to the different stationary phases; hence the optimal can be selected. The choice of basic alumina, modified to activity IV, as a suitable stationary phase has allowed isolation of certain iodoaziridines in excellent yield and purity.

A protocol for the diastereoselective one-pot preparation of cis-N-Ts-iodoaziridines is described. The generation of diiodomethyllithium, addition to N-Ts aldimines and cyclization of the amino gem-diiodide intermediate to iodoaziridines is demonstrated. Also included is a protocol to rapidly and quantitatively assess the most appropriate stationary phase for purification by chromatography.

クロマトグラフィーのための最適な固定相の定量的な選択を伴う合成とIodoaziridinesの精製

The highly diastereoselective preparation of cis-N-Ts-iodoaziridines through reaction of diiodomethyllithium with N-Ts aldimines is described. ...

化学

A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products

The guanidine functional group, displayed most prominently in the amino acid arginine, one of the fundamental building blocks of life, is an important structural element found in many complex natural products and pharmaceuticals. Owing to the continual discovery of new guanidine-containing natural products and designed small molecules, rapid and efficient guanidinylation methods are of keen interest to synthetic and medicinal organic chemists. Because the nucleophilicity and basicity of guanidines can affect subsequent chemical transformations, traditional, indirect guanidinylation is typically pursued. Indirect methods commonly employ multiple protection steps involving a latent amine precursor, such as an azide, phthalimide, or carbamate. By circumventing these circuitous methods and employing a direct guanidinylation reaction early in the synthetic sequence, it was possible to forge the linear terminal guanidine containing backbone of clavatadine A to realize a short and streamlined synthesis of this potent factor XIa inhibitor. In practice, guanidine hydrochloride is elaborated with a carefully constructed protecting array that is optimized to survive the synthetic steps to come. In the preparation of clavatadine A, direct guanidinylation of a commercially available diamine eliminated two unnecessary steps from its synthesis. Coupled with the wide variety of known guanidine protecting groups, direct guanidinylation evinces a succinct and efficient practicality inherent to methods that find a home in a synthetic chemist&#39;s toolbox.

Here, we present a protocol for direct, early stage guanidinylation that enables rapid total synthesis of aminoguanidine-containing small organic molecules. An advanced synthetic intermediate used in the synthesis of a blood coagulation factor XIa inhibitor was prepared using this protocol.

複雑なアミノグアニジン含有天然物の合成のための直接、早期グアニジニルプロトコル

The guanidine functional group, displayed most prominently in the amino acid arginine, one of the fundamental building blocks of life, is an important ...

Method for Efficient Refolding and Purification of Chemoreceptor Ligand Binding Domain

Identification of natural ligands of chemoreceptors and structural studies aimed at elucidation of the molecular basis of the ligand specificity can be greatly facilitated by the production of milligram amounts of pure, folded ligand binding domains. Attempts to heterologously express periplasmic ligand binding domains of bacterial chemoreceptors in Escherichia coli (E. coli) often result in their targeting into inclusion bodies. Here, a method is presented for protein recovery from inclusion bodies, its refolding and purification, using the periplasmic dCACHE ligand binding domain of Campylobacter jejuni (C. jejuni) chemoreceptor Tlp3 as an example. The approach involves expression of the protein of interest with a cleavable His6-tag, isolation and urea-mediated solubilisation of inclusion bodies, protein refolding by urea depletion, and purification by means of affinity chromatography, followed by tag removal and size-exclusion chromatography. The circular dichroism spectroscopy is used to confirm the folded state of the pure protein. It has been demonstrated that this protocol is generally useful for production of milligram amounts of dCACHE periplasmic ligand binding domains of other bacterial chemoreceptors in a soluble and crystallisable form.

A procedure is presented for the refolding of the dCACHE periplasmic ligand binding domain of Campylobacter jejuni chemoreceptor Tlp3 from inclusion bodies and the purification to yield milligram quantities of protein.

高効率巻き戻しと受容体リガンド結合領域の浄化法

Identification of natural ligands of chemoreceptors and structural studies aimed at elucidation of the molecular basis of the ligand specificity can be ...

生化学

The Synthesis of [Sn10(Si(SiMe3)3)4]2- Using a Metastable Sn(I) Halide Solution Synthesized via a Co-condensation Technique

The number of well-characterized metalloid tin clusters, synthesized by applying the disproportionation of a metastable Sn(I) halide in the presence of a sterically demanding ligand, has increased in recent years. The metastable Sn(I) halide is synthesized at&#160;&#34;outer space conditions&#34; via the preparative co-condensation technique. Thereby, the subhalide is synthesized in an oven at high temperatures, around 1,300 &#176;C, and at reduced pressure by the reaction of elemental tin with hydrogen halide gas (e.g., HCl). The subhalide (e.g., SnCl) is trapped within a matrix of an inert solvent, like toluene at -196 &#176;C. Heating the solid matrix to -78 &#176;C gives a metastable solution of the subhalide. The metastable subhalide solution is highly reactive but can be stored at -78 &#176;C for several weeks. On heating the solution to room temperature, a disproportionation reaction occurs, leading to elemental tin and the corresponding dihalide. By applying bulky ligands like Si(SiMe3)3, the intermediate metalloid cluster compounds can be trapped before complete disproportionation to elemental tin. Hence, the reaction of a metastable Sn(I)Cl solution with Li-Si(SiMe3)3 gives [Sn10(Si(SiMe3)3)4]2- 1 as black crystals in high yield. 1 is formed via a complex reaction sequence including salt metathesis, disproportionation, and degradation of larger clusters. Further, 1 can be analyzed by various methods like NMR or single crystal X-ray structure analysis.

The Synthesis of [Sn10SiSiMe334]2- Using a Metastable SnI Halide Solution Synthesized via a Co-condensation Technique

The disproportionation reaction of a metastable Sn(I) chloride solution, obtained via the preparative co-condensation technique, is used for the synthesis of a metalloid tin cluster compound.

[Snとの合成<sub&gt; 10</sub&gt;シリコン（Si（サイム<sub&gt; 3</sub&gt;）<sub&gt; 3</sub&gt;）<sub&gt; 4</sub&gt;]<sup&gt; 2</sup<sup&gt; -</sup&gt;準安定のSn（I）の共縮技術を介して合成ハロゲン化物溶液を使用しました

The number of well-characterized metalloid tin clusters, synthesized by applying the disproportionation of a metastable Sn(I) halide in the presence of a ...

A Dual-Functional Electroactive Filter Towards Simultaneously Sb(III) Oxidation and Sequestration

We have designed a facile method to synthesize a dual-functional electrochemical filter consisting of two 1-D materials: titanate nanowires and carbon nanotubes. The hybrid titanate-CNT filter was prepared by a sonication coupled with a post-filtration route. Due to the synergistic effects of the increased number of exposed sorption sites, electrochemical reactivity, small pore size of the titanate-CNT network coupled with a flow-through design, simultaneous Sb(III) oxidation and sequestration can be readily achieved. Atomic fluorescence spectrometer technology demonstrated that the applied electrical field accelerates the Sb(III) conversion rate and the as-obtained Sb(V) were adsorbed effectively by the titanate nanowires due to their Sb specificity. This protocol provides a practical solution for the removal of highly toxic Sb(III) and other similar heavy metal ions.

A Dual-Functional Electroactive Filter Towards Simultaneously SbIII Oxidation and Sequestration

A protocol for the rational design of a dual-functional electroactive filter consisting of carbon nanotubes and titanate nanowires is reported and their environmental applications towards Sb(III) oxidation and sequestration is presented.

Sb(III) 酸化と隔離を同時に行う二重機能電気活性フィルタ

We have designed a facile method to synthesize a dual-functional electrochemical filter consisting of two 1-D materials: titanate nanowires and carbon ...

環境学

Synthesis of a Thiol Building Block for the Crystallization of a Semiconducting Gyroidal Metal-sulfur Framework

We present a method for preparing thioester molecules as the masked form of the thiol linkers and their utilization for accessing a semiconducting and porous metal-dithiolene network in the highly ordered single crystalline state. Unlike the highly reactive free-standing thiols, which tend to decompose and complicate the crystallization of metal-thiolate open frameworks, the thioester reacts in situ to provide the thiol species, serving to mitigate the reaction between the mercaptan units and the metal centers, and to improve crystallization consequently. Specifically, the thioester was synthesized in a one-pot procedure: an aromatic bromide (hexabromotriphenylene) reacted with excess sodium thiomethoxide under vigorous conditions to first form the thioether intermediate product. The thioether was then demethylated by the excess thiomethoxide to provide the thiolate anion that was acylated to form the thioester product. The thioester was conveniently purified by standard column chromatography, and then used directly in the framework synthesis, wherein NaOH and ethylenediamine serve to revert in situ the thioester to the thiol linker for assembling the single-crystalline Pb(II)-dithiolene network. Compared with other methods for thiol synthesis (e.g., by cleaving alkyl thioether using sodium metal and liquid ammonia), the thioester synthesis here uses simple conditions and economical reagents. Moreover, the thioester product is stable and can be conveniently handled and stored. More importantly, in contrast to the generic difficulty in accessing crystalline metal-thiolate open frameworks, we demonstrate that using the thioester for in situ formation of the thiol linker greatly improves the crystallinity of the solid-state product. We intend to encourage broader research efforts on the technologically important metal-sulfur frameworks by disclosing the synthetic protocol for the thioester as well as the crystalline framework solid.

Here, we present a one-pot, transition-metal-free synthesis of thiols and thioesters from aromatic halides and sodium thiomethoxide, followed by the preparation of single crystals of a metal-dithiolene network using thiol species generated in situ from the more stable and tractable thioester.

半導体 Gyroidal 金属硫黄フレームワークの結晶化に対するチオール ビルディング ブロックの合成

We present a method for preparing thioester molecules as the masked form of the thiol linkers and their utilization for accessing a semiconducting and ...

Separation of Aldehydes and Reactive Ketones from Mixtures Using a Bisulfite Extraction Protocol

The purification of organic compounds is an essential component of routine synthetic operations. The ability to remove contaminants into an aqueous layer by generating a charged structure provides an opportunity to use extraction as a simple purification technique. By combining the use of a miscible organic solvent with saturated sodium bisulfite, aldehydes and reactive ketones can be successfully transformed into charged bisulfite adducts that can then be separated from other organic components of a mixture by the introduction of an immiscible organic layer. Here, we describe a simple protocol for the removal of aldehydes, including sterically-hindered neopentyl aldehydes and some ketones, from chemical mixtures. Ketones can be separated if they are sterically unhindered cyclic or methyl ketones. For aliphatic aldehydes and ketones, dimethylformamide is used as the miscible solvent to improve removal rates. The bisulfite addition reaction can be reversed by basification of the aqueous layer, allowing for the re-isolation of the reactive carbonyl component of a mixture.

Here, we present a protocol to remove aldehydes and reactive ketones from mixtures by a liquid-liquid extraction protocol directly with saturated sodium bisulfite in a miscible solvent. This combined protocol is rapid and facile to perform. The aldehyde or ketone can be re-isolated by the basification of the aqueous layer.

アルデヒドおよびケトン類の反応性の重亜硫酸塩の抽出のプロトコルを使用して混合物からの分離

The purification of organic compounds is an essential component of routine synthetic operations. The ability to remove contaminants into an aqueous layer ...

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.

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

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

脂質バイセルにおけるABCトランスポーター膜タンパク質の結晶化

ABCG5/G8 Crystallization in a Lipidic Bicelle Environment for X-Ray Crystallography

ATP-binding cassette (ABC) transporters constitute lipid-embedded membrane proteins. Extracting these membrane proteins from the lipid bilayer to an aqueous environment is typically achieved by employing detergents. These detergents disintegrate the lipid bilayer and solubilize the proteins. The intrinsic habitat of membrane proteins within the lipid bilayer poses a challenge in maintaining their stability and uniformity in solution for structural characterization. Bicelles, which comprise a blend of long and short-chain phospholipids and detergents, replicate the natural lipid structure. The utilization of lipid bicelles and detergents serves as a suitable model system for obtaining high-quality diffraction crystals, specifically to determine the high-resolution structure of membrane proteins. Through these synthetic microenvironments, membrane proteins preserve their native conformation and functionality, facilitating the formation of three-dimensional crystals. In this approach, the detergent-solubilized heterodimeric ABCG5/G8 was reintegrated into DMPC/CHAPSO bicelles, supplemented with cholesterol. This setup was employed in the vapor diffusion experimental procedure for protein crystallization.

著者スポットライト:医薬品開発を進めるためのABCトランスポーター膜タンパク質のバイセル結晶化セットアップ 

This protocol describes a setup for the crystallization of the sterol transporter ABCG5/G8. ABCG5/G8 is reconstituted into bicelles for hanging-drop crystallization. The protocol does not require specialized materials or substrates, making it accessible and easy to adapt in any laboratory for determining the protein structure through X-ray crystallography.

脂質バイセル環境下でのABCG5/G8結晶化によるX線結晶構造解析

ATP-binding cassette (ABC) transporters constitute lipid-embedded membrane proteins. Extracting these membrane proteins from the lipid bilayer to an ...

ビスiminoguanidiniumリガンドと選択的結晶化により硫酸の分離

要約

さらに動画を探す

この動画の章

クロマトグラフィーのための最適な固定相の定量的な選択を伴う合成とIodoaziridinesの精製

複雑なアミノグアニジン含有天然物の合成のための直接、早期グアニジニルプロトコル

高効率巻き戻しと受容体リガンド結合領域の浄化法

[Snとの合成

Sb(III) 酸化と隔離を同時に行う二重機能電気活性フィルタ

半導体 Gyroidal 金属硫黄フレームワークの結晶化に対するチオールビルディングブロックの合成

アルデヒドおよびケトン類の反応性の重亜硫酸塩の抽出のプロトコルを使用して混合物からの分離

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

脂質バイセル環境下でのABCG5/G8結晶化によるX線結晶構造解析

脂質バイセル環境下でのABCG5/G8結晶化によるX線結晶構造解析

ビスiminoguanidiniumリガンドと選択的結晶化により硫酸の分離

要約

さらに動画を探す

この動画の章

クロマトグラフィーのための最適な固定相の定量的な選択を伴う合成とIodoaziridinesの精製

複雑なアミノグアニジン含有天然物の合成のための直接、早期グアニジニルプロトコル

高効率巻き戻しと受容体リガンド結合領域の浄化法

[Snとの合成

Sb(III) 酸化と隔離を同時に行う二重機能電気活性フィルタ

半導体 Gyroidal 金属硫黄フレームワークの結晶化に対するチオール ビルディング ブロックの合成

アルデヒドおよびケトン類の反応性の重亜硫酸塩の抽出のプロトコルを使用して混合物からの分離

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

脂質バイセル環境下でのABCG5/G8結晶化によるX線結晶構造解析

脂質バイセル環境下でのABCG5/G8結晶化によるX線結晶構造解析

半導体 Gyroidal 金属硫黄フレームワークの結晶化に対するチオールビルディングブロックの合成