ボロンと融合した二重ヘリケンの2段階合成
Takazumi Katayama1, Soichiro Nakatsuka1, Hiroki Hirai1
1Department of Chemistry, School of Science and Technology, Kwansei Gakuin University , 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
Journal of the American Chemical Society
|April 15, 2016
まとめ
3D π スタッキングにより優れたアンビポーラ伝導性を示す新しいボロン融合ドブル [5] ヘリケンが合成された. Tert-ブチル群は光学的解像度を可能にし,円形に偏光した深青の光エナントイオマーを生成した.
科学分野:
- 有機化学
- 材料科学
- 超分子化学
背景:
- ヘリケンは独特の3次元構造を持つキラル型多循環型芳香炭化水素である.
- 先進的な材料に合わせた電子的,光学的性質を持つ新しいヘリケンの誘導体の開発は極めて重要です.
- ラセミゼーションの制御とエナティオメア純度の達成は,ヘリケンの化学における主要な課題である.
研究 の 目的:
- 新型ボロン融合ドブルヘリケーン [5]を合成する.
- これらの新しいヘリケンの誘導体の電子と光学的性質を調査する.
- ヘリケンの安定性と光学解像度に対するテルブチル置換の影響を調査する.
主な方法:
- ハート反応とヘクサブロムベンゼンから始まる脱メチル化サイクルを含む2段階の合成.
- 投光学および分析技術を用いて合成されたボロン溶融の二重ヘリケンの特徴づけ [5]
- 電気伝導性と光物理学的性質の評価,光と円形の偏光を含む.
主要な成果:
- 新型ボロン融合ドブルヘリケンの合成に成功.
- 両親のヘリケンは,ユニークな3Dレンガの π 積み重ねの配置に起因する優れた両極伝導性を示しました.
- 4つのテルブチル基を導入することで,光学解像度が促進され,ラセミ化が効果的に抑制されました.
- エナティオメリカルに純粋なヘリケンは深青色 (CIE座標0.15,0.08) を示し,円形の偏光活性を示した.
結論:
- 開発された合成経路は,新しいボロン溶融の二重ヘリケーン [5]へのアクセスを提供します.
- これらのヘリケンは有望な二極伝導性と調節可能な光物理的特性を有しています.
- テートブチル群の導入戦略は,光学的解像度を実現し,カイロプティカルデバイスで潜在的なアプリケーションを持つエナチオプア材料にアクセスするのに有効です.
関連する概念動画
03:08Hydroboration-Oxidation of Alkenes
12.1K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
12.1K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
21.8K
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
21.8K
02:36Regioselectivity and Stereochemistry of Hydroboration
9.7K
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
9.7K
02:46Halogenation of Alkenes
21.0K
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
21.0K
03:24Hybridization of Atomic Orbitals I
69.2K
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
69.2K
01:14Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
3.9K
Electrophilic addition of halogens to alkenes proceeds via a cyclic halonium ion to form a 1,2-dihalide or a vicinal dihalide.
3.9K