軽度な条件下でボリル化されたトリアゼンとテトラゼンを含む複合ボロン-窒素異環の合成
Dominic Prieschl1,2, Guillaume Bélanger-Chabot1,2, Xueying Guo3
1Institute for Inorganic Chemistry , Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany.
Journal of the American Chemical Society
|December 13, 2019
まとめ
有機アジドはディボランと反応して,新しい5つまたは6つの環を形成する. これらのボリルトリアゼンには独特の構造とアリル移動があり,ボロン化学を拡張します.
科学分野:
- オーガノボロン化学
- 合成有機化学
- ヘテロサイクル化学
背景:
- オーガニック・アジドとディボランの反応の探求
- 1,2,3-トリアゾロトボラン以外にも,ボリルトリアゼンが限られている.
研究 の 目的:
- オーガニック・アジドとダイアリル・ディハロ・ディボランの反応パターンを研究する.
- ボロンと窒素を含む新しいヘテロサイクル化合物を合成し,特徴づけます.
- 観察された変換のための機械的経路を提案する.
主な方法:
- フェニルアジドと1,2-ディアリル-1,2-ジハロディボランの反応
- フェニルアジドと1,1-di(9-アントリル) -2,2-ディフローロジボランの反応
- トリメチルシリルアジドをアジド移転反応剤として使用した置換反応.
- 量子化学計算で裏付けられた 機械的な洞察
主要な成果:
- B-B結合を保持した5基のディボリル-トリアゼン環の形成.
- B-B結合裂けとアリルニトレン中間体による6基のディボリルトリアゼン環の合成.
- ボールからアジド窒素へのアリル移動の観察.
- ボリルテトラザボロールとディボリルジアジボレチドンの生成,N-ボリル置換のイミノボランの証拠.
結論:
- ディボランと有機アジドの新しい反応パターンが発見された.
- 独特の結合性を持つ前例のないボリルトリアゼンヘテロサイクルが合成されました.
- この研究は,ボロン-窒素ヘテロサイクルの範囲を拡大し,機械的理解を提供します.
関連する概念動画
03:08Hydroboration-Oxidation of Alkenes
10.9K
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.
10.9K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
20.5K
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.
20.5K
02:36Regioselectivity and Stereochemistry of Hydroboration
9.3K
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.
9.3K
01:20Electrophilic Aromatic Substitution: Nitration of Benzene
8.0K
The nitration of benzene is an example of an electrophilic aromatic substitution reaction. It involves the formation of a very powerful electrophile, the nitronium ion, which is linear in shape. The reaction occurs through the interaction of two strong acids, sulfuric and nitric acid.
8.0K
01:12Preparation of Nitriles
2.5K
One of the common methods to prepare nitriles is the dehydration of amides. This method requires strong dehydrating agents like phosphorous pentoxide or boiling acetic anhydride for converting amides to nitriles. Another reagent namely, thionyl chloride also accomplishes the dehydration of amides, where amide acts as a nucleophile. The first step of the mechanism involves the nucleophilic attack by the amide on the thionyl chloride to form an intermediate. In the next step, the electron pairs...
2.5K
01:18Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
2.6K
Birch reduction uses solvated electrons as reducing agents. The reaction converts benzene to 1,4-cyclohexadiene. The reaction proceeds by the transfer of a single electron to the ring to form a benzene radical anion. This anion is highly basic—it abstracts a proton from the alcohol to form a cyclohexadienyl radical. Another single electron transfer gives the cyclohexadienyl anion. A proton transfer from the alcohol forms 1,4-cyclohexadiene. Since this reduction occurs via radical anion...
2.6K