リサイクル可能な有機水素でCOをメタノールに還元する
Andressa V Müller1, Shahbaz Ahmad1, Jake T Sirlin2
1Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States.
Journal of the American Chemical Society
|March 20, 2024
まとめ
研究者は,有機水素還元剤と可視光を用いて,移行金属カルボニル複合体をヒドロキシメチル複合体に変換する反応ステップを定量化しました. これは,COまたはCO2からメタノールを生産するための選択的な経路を提供します.
科学分野:
- 有機金属化学
- 写真化学
- カタリシス
背景:
- 移行金属カルボニル複合体は,CO削減における重要な中間物質である.
- オーガニック・ヒドリド・リダクタントは 化学的変換の持続可能な代替手段を提供します
- メタノールなどの有価な製品に CO を選択的に変換することは大きな課題です
研究 の 目的:
- 移行金属カルボニル複合体からヒドロキシメチル複合体への選択的変換の反応段階を定量化する.
- ディヒドロベンジミダゾール有機水素減量剤を用いたCO減量のメカニズムを調査する.
- ハイドロキシメチル複合体からの可視光誘発メタノール放出を示す.
主な方法:
- 製品識別と定量化のための光譜分析 (1H NMR) とガス染色学.
- 反応の順序と活性化パラメータを決定する運動実験.
- ディヒドロベンジミダゾールの電気化学的および光化学的再生
主要な成果:
- ディヒドロベンジミダゾールを用いてcis-[Ru(bpy) 2 ((CO) 2) 2+からホルミールおよびヒドロキシメチルルテニウム複合体の選択的形成.
- 運動研究により,電子伝送-プロトン結合電子伝送 (ET-PCET) 機構が示唆されている.
- ハイドロキシメチル複合体の可視光照射は,メタノールを高選択性で放出する.
結論:
- ディヒドロベンジミダゾール有機水素は,温和な条件下で,選択的にCOをメタノールに還元します.
- 反応経路には,連続した還元とプロトネーションのステップが含まれます.
- このアプローチは,COまたはCO2から持続可能なメタノール生産のための実行可能な戦略を示しています.
関連する概念動画
02:23Alcohols from Carbonyl Compounds: Reduction
10.4K
Reduction is a simple strategy to convert a carbonyl group to a hydroxyl group. The three major pathways to reduce carbonyls to alcohols are catalytic hydrogenation, hydride reduction, and borane reduction.
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
10.4K
01:19Acid Halides to Alcohols: LiAlH4 Reduction
2.8K
Acid halides are reduced to alcohols in the presence of a strong reducing agent like lithium aluminum hydride.
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
2.8K
01:17Carboxylic Acids to Primary Alcohols: Hydride Reduction
2.8K
Carboxylic acids, upon reaction with strong reducing agents such as lithium aluminum hydride followed by hydrolysis, undergo reduction to form primary alcohols.
2.8K
01:09Aldehydes and Ketones to Alkanes: Wolff–Kishner Reduction
4.5K
Wolff–Kishner reduction involves converting aldehydes and ketones to alkanes using hydrazine and a base. The reaction converts a carbonyl group to a methylene group. The method was independently discovered by N. Kishner in 1911 and L. Wolff in 1912. The reduction is carried out in high-boiling solvents such as ethylene glycol and diethylene glycol because heat is required to deprotonate the N–H proton in one of the reaction steps. ...
4.5K
01:17Esters to Alcohols: Hydride Reductions
3.5K
Esters are reduced to primary alcohols when treated with a strong reducing agent like lithium aluminum hydride. The reaction requires two equivalents of the reducing agent and proceeds via an aldehyde intermediate.
Lithium aluminum hydride is a source of hydride ions and functions as a nucleophile. The mechanism proceeds in three steps. Firstly, the nucleophilic hydride ion attacks the carbonyl carbon of the ester to form a tetrahedral intermediate. Subsequently, the carbonyl group re-forms,...
Lithium aluminum hydride is a source of hydride ions and functions as a nucleophile. The mechanism proceeds in three steps. Firstly, the nucleophilic hydride ion attacks the carbonyl carbon of the ester to form a tetrahedral intermediate. Subsequently, the carbonyl group re-forms,...
3.5K
03:08Hydroboration-Oxidation of Alkenes
8.2K
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.
8.2K