ニール/キラル・ナトリウム・カルボキシラート 二重触媒による非対称O-プロパルギレーション
Xianghong Xu1, Lingzi Peng1, Xihao Chang1
1Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
Journal of the American Chemical Society
|December 3, 2021
まとめ
新しいニッケル触媒によるO-プロパルギレーション反応により,高い選択性を持つキラルヒドロキシラミンが生成される. この効率的な方法は 軽い条件を利用し,ルシフェラーゼ阻害剤のような複雑な分子を合成するのに役立ちます.
科学分野:
- 有機化学
- キャタリシス
- 非対称合成
背景:
- 有機化学では,エナチオ濃縮化合物を合成するための効率的な触媒方法の開発が不可欠です.
- 化学変換中のステレオ化学を制御する上で,キラル補助物質と触媒は重要な役割を果たします.
研究 の 目的:
- 新しい触媒システムを用いて高度にエナチオセレクティブなO-プロパルギレーション反応を開発する.
- 酵素濃縮されたO-プロパルギルヒドロキシラミンの合成のための開発された触媒システムの範囲と限界を調査する.
主な方法:
- フォスフィン-ニッケル複合体と軸性キラルナトリウム二酸化炭素を組み合わせた触媒系を用いた.
- 反応条件は軽度,広範囲の基板,機能的群耐性のために最適化されました.
主要な成果:
- 開発された触媒システムは,ヒドロキシラミンのO-プロパルギレーションにおいて高いエナチオ選択性を達成した.
- この反応は優れた機能群耐性を示し,様々なエンアンチオ濃縮O-プロパルギルヒドロキシラミンの合成を可能にしました.
- この方法は,のルシフェラーゼ阻害剤と (S) - 二水素シャブシケトールの非対称的全合成に成功しました.
結論:
- ニッケル触媒の対流体としてキラルナトリウム二酸化炭素を用いた新しく効率的なエナンチオセレクティブO-プロパルギレーションが確立された.
- この方法論は,価値あるエナチオ濃縮O-プロパルギルヒドロキシラミンとその複合派生体を入手するための強力なツールを提供します.
関連する概念動画
02:23SN2 Reaction: Stereochemistry
10.1K
In an SN2 reaction, the nucleophilic attack on the substrate and departure of the leaving group occurs simultaneously through a transition state. As the nucleophile approaches the substrate from the back-side, the configuration of the substrate carbon changes from tetrahedral to trigonal bipyramidal and then back to tetrahedral, leading to an inversion in the configuration of the product.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...
10.1K
02:05Prochirality
4.1K
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
4.1K
02:15SN1 Reaction: Stereochemistry
9.1K
This lesson provides an in-depth discussion of the stereochemical outcomes in an SN1 reaction.
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
9.1K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.5K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.5K
02:36Regioselectivity and Stereochemistry of Hydroboration
8.5K
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...
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...
8.5K
01:10α-Alkylation of Ketones via Enolate Ions
3.3K
Ketones with α protons are deprotonated by strong bases like lithium diisopropylamide (LDA) to form enolate ions. The anion is stabilized by resonance, and its hybrid structure exhibits negative charges on the carbonyl oxygen and the α carbon. This ambident nucleophile can attack an electrophile via two possible sites: the carbonyl oxygen, known as O-attack, or the α carbon, known as C-attack. The nucleophilic attack via the carbanionic site is preferred. This is due to the...
3.3K