フェロセニルヒドリドボラート:合成,構造的特徴化,およびフェロセニルボランポリマーの製剤への応用
Matthias Scheibitz1, Haiyan Li, Jan Schnorr
1Institut für Anorganische und Analytische Chemie, Johann Wolfgang Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, D-60438 Frankfurt am Main, Germany.
Journal of the American Chemical Society
|October 20, 2009
まとめ
新しいフェロセニルボランポリマーが合成され,特徴づけられました. これらの新しい材料は,より小さな分子と比較して赤にシフトしたUV-vis吸収を含むユニークな特性を発揮し,材料科学における潜在的な応用を示しています.
科学分野:
- 有機金属化学 有機金属化学
- ポリマー化学のポリマー化学について
- マテリアルサイエンス 材料科学
背景:
- フェロセンの誘導体は,有機金属化学における多用途な構成要素である.
- ボラン化合物は,ユニークな反応性と構造的多様性を提供します.
- 電子特性を合わせた新しいポリマー材料の開発は,大きな関心を持っています.
研究 の 目的:
- 新型モノ・ディトピックリチウム・フェロセニルヒドリドボレーツの合成と特徴付け.
- これらのボラートとその対応するボランの反応性を調査する.
- 新しいフェロセニルボランポリマーを開発し,その性質を研究する.
主な方法:
- フェロセニルボロン前駆体とリチウムアルミニウム水化物を使用してリチウムフェロセニル水化ドボラートの合成.
- 集積物の構造的決定のためのX線結晶学.
- ボラートとトリメチルシリル塩化物の反応により,ボランが生成される.
- NMR,IR,UV-vis,MALDI-TOF質量スペクトロメトリを用いたフェロセニルボランポリマーのポリメリゼーションと特徴付け.
主要な成果:
- モノ・ディトピック・リチウム・フェロセニル・ヒドリドボラートとディメリク・テトメリク・アグレガートを合成した.
- フェロセニルボランの生成とその後の凝縮によりフェロセニルボランポリマーが形成されます.
- ボロンに結合したビニル基を含む新型フェロセニルボランポリマーを合成し,赤色移転した紫外線に対する吸収を示す.
結論:
- この研究は,新しいフェロセニルボランポリマーへの簡単な経路を示しています.
- 合成されたポリマーは,その拡張結合によりユニークな電子特性を持っています.
- これらの発見は,新しい機能的な有機金属ポリマーの開発への道を開きます.
関連する概念動画
03:08Hydroboration-Oxidation of Alkenes
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.
02:36Regioselectivity and Stereochemistry of Hydroboration
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.
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
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.
01:17Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
02:15Preparation of Alcohols via Addition Reactions
Overview
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
01:18Aromatic Hydrocarbon Cations: Structural Overview
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
Removing one hydrogen from the intervening CH2 group with both...