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><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>&lt;em&gt;N&lt;/em&gt;-Bromosuccinimide (NBS)</td><td>Sigma Aldrich</td><td>B8.125-5</td><td>ReagentPlus&amp;reg;, 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&amp;reg;, &amp;ge;99.5%.</td></tr><tr><td>Gold(III) chloride Hydrate</td><td>Sigma Aldrich</td><td>50778</td><td>puriss. p.a., ACS reagent, &amp;ge;49% Au basis.</td></tr><tr><td>Ethynyltrimethylsilane</td><td>Sigma Aldrich</td><td>218170</td><td>98%</td></tr><tr><td>[PdCl&lt;sub&gt;2&lt;/sub&gt;(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, &amp;ge;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 (CCl&lt;sub&gt;4&lt;/sub&gt;)</td><td>Fluka</td><td>87030</td><td>For IR spectroscopy, &amp;ge;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&amp;reg;, 99%.</td></tr><tr><td>Methanol (MeOH)</td><td>VWR</td><td>20847.36</td><td>AnalaR NORMAPUR.</td></tr><tr><td>Triethyl amine (NEt&lt;sub&gt;3&lt;/sub&gt;)</td><td>Sigma Aldrich</td><td>T0886</td><td>&amp;ge;99%</td></tr><tr><td>Silica gel</td><td>Acros</td><td>360050010</td><td>Particle size 40-60 mm.</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 F&lt;sub&gt;254&lt;/sub&gt;</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 ...

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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

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.

生成Cyanocarbenesの適用のための超原子価ヨードニウムアルキニルトリフラートの合成

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

化学

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 ...

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Bicyclic aziridinium ions were generated by the removal of an appropriate leaving group through internal nucleophilic attack by nitrogen atom in the aziridine ring. The utility of bicyclic aziridinium ions, specifically 1-azoniabicyclo[3.1.0]hexane and 1-azoniabicyclo[4.1.0]heptane tosylate highlighted in the aziridine ring openings by the nucleophile with the release of the ring strain to yield the corresponding ring-expanded azaheterocycles such as pyrrolidine, piperidine and azepane with diverse substituents on the ring in regio- and stereospecific manner. Herein, we report a simple and convenient method for the preparation of the stable 1-azabicyclo[4.1.0]heptane tosylate followed by selective ring opening via a nucleophilic attack either at the bridge or at the bridgehead carbon to yield piperidine and azepane rings, respectively. This synthetic strategy allowed us to prepare biologically active natural products containing piperidine and azepane motif including sedamine, allosedamine, fagomine and balanol in highly efficient manner.

Bicyclic aziridinium ions such as 1-azoniabicyclo[4.1.0]heptane tosylate were generated from 2-[4-tolenesulfonyloxybutyl]aziridine, which was utilized for the preparation of substituted piperidines and azepanes via regio- and stereospecific ring-expansion with various nucleophiles. This highly efficient protocol allowed us to prepare diverse azaheterocycles including natural products such as fagomine, febrifugine analogue and balanol.

安定した二環性 Aziridinium イオンと開環の Azaheterocycles の合成のための準備

Bicyclic aziridinium ions were generated by the removal of an appropriate leaving group through internal nucleophilic attack by nitrogen atom in the ...

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.

1-Iodoalkynes、1, 2-Diiodoalkenes、末端アルキンの酸化ヨウ素化に基づく 1,1,2 Triiodoalkenes の化学選択的準備

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

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals

Protocols for the isolation of the commonly employed cyclic (alkyl)(amino) carbene (CAAC) and N-heterocyclic carbene (NHC) are reported. Furthermore, the synthesis of their mixed CAAC&#8211;NHC &#8220;Wanzlick&#8221; dimer and the synthesis of the related stable organic &#8220;olefin&#8221; radical are presented. The main goal of this manuscript is to give a detailed and general protocol for the synthetic chemist of any skill level on how to prepare free heterocyclic carbenes by deprotonation using filter cannulas. Due to the air-sensitivity of the synthesized compounds, all experiments are performed under inert atmosphere using either Schlenk technique or a dinitrogen filled glovebox. Controlling Wanzlick&#8217;s equilibrium (i.e., the dimerization of free carbenes), is a crucial requirement for the application of free carbenes in coordination chemistry or organic synthesis. Thus, we elaborate on the specific electronic and steric requirements favoring the formation of dimers, heterodimers, or monomers. We will show how proton catalysis allows for the formation of dimers, and how the electronic structure of carbenes and their dimers affects the reactivity with either moisture or air. The structural identity of the reported compounds is discussed based on their NMR spectra.

We present protocols for the isolation of stable heterocyclic carbenes. The synthesis of a cyclic (alkyl)(amino) carbene (CAAC) and an N-heterocyclic carbene (NHC) is demonstrated using filter cannulas and Schlenk technique. We furthermore present the synthesis of the related oxygen-sensitive, electron-rich mixed &#8220;Wanzlick dimer&#8221; and the reduced stable organic radical.

無料カルベン、混合二量体および有機ラジカルを分離します。

Protocols for the isolation of the commonly employed cyclic (alkyl)(amino) carbene (CAAC) and N-heterocyclic carbene (NHC) are reported. Furthermore, the ...

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 ...

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions

Aziridines, a class of reactive organic molecules containing a three-membered ring, are important synthons for the synthesis of a large variety of functionalized nitrogen-containing target compounds through the regiocontrolled ring-opening of C-substituted aziridines. Despite the tremendous progress in aziridine synthesis over the past decade, accessing contiguous bisaziridines efficiently remains difficult. Therefore, we were interested in synthesizing contiguous bisaziridines bearing an electronically diverse set of N-substituents beyond the single aziridine backbone for regioselective ring-opening reactions with diverse nucleophiles. In this study, chiral contiguous bisaziridines were prepared by organocatalytic asymmetric aziridination of chiral (E)-3-((S)-1-((R)-1-phenylethyl)aziridin-2-yl)acrylaldehyde with N-Ts-O-tosyl or N-Boc-O-tosyl hydroxylamine as the nitrogen source in the presence of (2S)-[diphenyl(trimethylsilyloxy)methyl]pyrrolidine as a chiral organocatalyst. Also demonstrated here are representative examples of regioselective ring-opening reactions of contiguous bisaziridines with a variety of nucleophiles such as sulfur, nitrogen, carbon, and oxygen, and the application of contiguous bisaziridines to the synthesis of multi-substituted chiral pyrrolidines by Pd-catalyzed hydrogenation.

Contiguous bisaziridines containing non-activated and activated aziridines were synthesized by asymmetric organocatalytic aziridinations and then subjected to chemoselective ring-opening reactions under acidic or basic conditions. The non-activated aziridine ring opens with less reactive nucleophiles under acidic conditions, whereas the activated aziridine ring opens with more reactive nucleophiles under basic conditions.

位置選択的開環反応のための連続ビサジリジンの調製

Aziridines, a class of reactive organic molecules containing a three-membered ring, are important synthons for the synthesis of a large variety of ...

Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common drugs used to manage and treat pain and inflammation. In 2016, a new class of boron functionalized NSAIDs (bora-NSAIDs) was synthesized under mild conditions via the copper-catalyzed regioselective boracarboxylation of vinyl arenes using carbon dioxide (CO2 balloon) and a diboron reductant at room temperature. This original method was performed primarily in a glovebox or with a vacuum gas manifold (Schlenk line) under rigorous air-free and moisture-free conditions, which often led to irreproducible reaction outcomes due to trace impurities. The present protocol describes a simpler and more convenient benchtop method for synthesizing a representative bora-NSAID, bora-ibuprofen. A Suzuki-Miyaura cross-coupling reaction between 1-bromo-4-isobutylbenzene and vinylboronic acid pinacol ester produces 4-isobutylstyrene. The styrene is subsequently boracarboxylated regioselectively to provide bora-ibuprofen, an &#945;-aryl-&#946;-boryl-propionic acid, with good yield on a multi-gram scale. This procedure allows for the broader utilization of copper-catalyzed boracarboxylation in synthetic laboratories, enabling further research on bora-NSAIDs and other unique boron-functionalized drug-like molecules.

The present protocol describes a detailed benchtop catalytic method that yields a unique borylated derivative of ibuprofen.&#160;

鈴木クロスカップリング反応とアルケンボラカルボキシル化反応によるホウ素化イブプロフェン誘導体の合成

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common drugs used to manage and treat pain and inflammation. In 2016, a new class of ...

Preparation of Alkynes: Alkylation Reaction

<h4>Introduction</h4>
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
<img alt="Figure1" src="/files/ftp_upload/11834/11834_PT_Figure_1.svg" style="text-align: center; height: 50px;" />
The reaction takes place in two steps:
1. The first step is the deprotonation of the terminal alkyne by the strong base forming an acetylide ion.
<img alt="Figure2" src="/files/ftp_upload/11834/11834_PT_Figure_2.svg" style="text-align: center; height: 50px;" />
2. The second step is a nucleophilic substitution reaction in which the acetylide ion reacts with the alkyl halide to form a new C&#8211;C bond.
<img alt="Figure3" src="/files/ftp_upload/11834/11834_PT_Figure_3.svg" style="text-align: center; height: 50px;" />
<h4>Reaction Mechanism &#8212;SN2 pathway </h4>
Acetylide ions are strong bases and can also function as good nucleophiles. The substitution reaction follows an SN2 pathway where the nucleophilic acetylide ion attacks the electrophilic carbon of the primary alkyl halide from the backside.
<img alt="Figure4" src="/files/ftp_upload/11834/11834_PT_Figure_4.svg" style="text-align: center; height: 250px;" />
Since this is a concerted process, the nucleophilic attack and the departure of the leaving group takes place simultaneously to form the product with an inverted stereochemistry at the reaction center.
The reaction works best with unhindered alkyl halides like methyl halide and other primary halides. With secondary and tertiary alkyl halides, acetylide ions act as strong bases, in which case E2 elimination is the preferred pathway.
<h4>Application in organic synthesis </h4>
Alkylation of simple terminal alkynes is a useful method to extend the length of the carbon chain. Acetylene, a terminal alkyne, can be converted to a higher internal alkyne by repeated alkylation as shown below:
<img alt="Figure5" src="/files/ftp_upload/11834/11834_PT_Figure_5.svg" style="text-align: center; height: 50px;" />

アルキンの調製:アルキル化反応

Introduction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for ...

有機化学

ユニット １

アルキン類

KEY TERMS AND CONCEPTS

Preparation of Alkynes: Dehydrohalogenation

<h4>Introduction</h4>
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ammonia. The reaction proceeds with the loss of two equivalents of hydrogen halide (HX) via two successive E2 elimination reactions.
<img alt="Figure1" src="/files/ftp_upload/11835/11835_PT_Figure_1.svg" style="text-align: center; height: 200px;" />
<h4>Reaction Mechanism &#8211; E2 pathway</h4>
Vicinal dihalides
In the first elimination step, the strong base abstracts the proton from the dihalide that is oriented anti to the leaving group. Since E2 reactions follow a concerted pathway, the abstraction of a proton and departure of the halide leaving group occur simultaneously to form a haloalkene.
<img alt="Figure2" src="/files/ftp_upload/11835/11835_PT_Figure_2.svg" style="text-align: center; height: 90px;" />
In the second elimination reaction, another equivalent of the strong base reacts with the haloalkene in a similar fashion to give the desired alkyne.
<img alt="Figure3" src="/files/ftp_upload/11835/11835_PT_Figure_3.svg" style="text-align: center; height: 90px;" />
Geminal dihalides
Likewise, geminal dihalides, when treated with two equivalents of a sodium amide, undergo double dehydrohalogenation to give alkynes.
<img alt="Figure4" src="/files/ftp_upload/11835/11835_PT_Figure_4.svg" style="text-align: center; height: 90px;" />
<img alt="Figure5" src="/files/ftp_upload/11835/11835_PT_Figure_5.svg" style="text-align: center; height: 90px;" />
Terminal dihalides 
Dehydrohalogenation of terminal dihalides yields terminal alkynes as the final product. In the presence of a strong base like sodium amide, terminal alkynes get converted to acetylide ions. In such cases, a third equivalent of the base is required to complete the dehydrohalogenation of the remaining haloalkene.
<img alt="Figure6" src="/files/ftp_upload/11835/11835_PT_Figure_6.svg" style="text-align: center; height: 70px;" />
Protonation of the acetylide ions with water or an aqueous acid completes the reaction.
<img alt="Figure7" src="/files/ftp_upload/11835/11835_PT_Figure_7.svg" style="text-align: center; height: 50px;" />
<h4>Application in Organic Synthesis</h4>
Dehydrohalogenation of vicinal dihalides is a useful intermediate step in the conversion of alkenes to alkynes. For example, chlorination of 1-propene gives 1,2-dichloropropane &#8211; a vicinal dihalide, which upon double dehydrohalogenation yields 1-propyne.
<img alt="Figure8" src="/files/ftp_upload/11835/11835_PT_Figure_8.svg" style="text-align: center; height: 60px;" />
Similarly, alkynes can also be synthesized from ketones via dehydrohalogenation of geminal dihalides. For example, treatment of acetone with phosphorous pentachloride yields 2,2-dichloropropane &#8211; a geminal dihalide, which undergoes double dehydrohalogenation to give 1-propyne.
<img alt="Figure9" src="/files/ftp_upload/11835/11835_PT_Figure_9.svg" style="text-align: center; height: 80px;" />

アルキンの調製:脱ハロゲン化水素

Introduction
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ...