関連する実験動画
Updated: Feb 13, 2026
09:53
Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture
Published on: May 13, 2018
8.7K
選別されたイリジウム触媒によって可能になったC-Hアミダーションによる γ-ラクタムの形成
Seung Youn Hong1, Yoonsu Park1, Yeongyu Hwang1
1Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea, and Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea.
Science (New York, N.Y.)
|March 3, 2018
まとめ
研究者は,カルボキシル酸誘導体から γ-ラクタムの効率的な合成のために,イリジウム (III) 触媒を最適化しました. この方法は以前の制限を克服し,選択的なC-Hアミデーションと複雑な分子の後期機能化を可能にします.
科学分野:
- 有機化学
- キャタリシス
- 薬剤化学
背景:
- γ-ラクトームを形成するためのC-H結合への分子内ナイトレンの挿入は,競合するイソシアネート形成のために困難です.
- γ-ラクタム合成のための効率的な触媒システムの開発は,薬剤の発見と開発に不可欠です.
研究 の 目的:
- 選択的なγ-ラクタム形成のためのペンタメチルcyclopentadienylイリジウムを最適化するために.
- 競合するイソシアネート経路を金属触媒化C-Hアミデーション反応で抑制する.
主な方法:
- 触媒設計の指針となる密度関数理論 (DFT) の計算.
- イリジウム (III) 触媒の合成と最適化
- 炭酸から派生したカルボニルニートレンの前駆体として1,4,2-ディオクサゾール-5-オンを使用する.
主要な成果:
- C-H挿入障壁を下げるための電子提供補助バイデントリガンドが特定されました.
- 最適化された触媒は,sp3とsp2のC-Hアミデーションによって高選択性を得ました.
- この方法は,アミノ酸派生物や生物活性分子を含む様々な基質を成功裏に機能させました.
結論:
- 計算上の研究と機械学的洞察により,非常に効果的なイリジウム (III) 触媒の開発が可能になった.
- このアプローチは,伝統的な合成の障害を克服し, γ-ラクトームへの堅牢で選択的な経路を提供します.
- この方法論は,薬学研究における遅い段階の機能化の大きな可能性を秘めています.
![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
関連する概念動画
01:29Preparation of Amides
4.1K
Amides are synthesized by treating carboxylic acids with amines in the presence of dehydrating agents like dicyclohexylcarbodiimide (DCC).
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
4.1K
01:28Amides to Carboxylic Acids: Hydrolysis
4.5K
Amides can undergo either acid-catalyzed hydrolysis or base-promoted hydrolysis through a typical nucleophilic acyl substitution. Each hydrolysis requires severe conditions.
Acid-catalyzed hydrolysis:
Hydrolysis of amides under acidic conditions yields carboxylic acids. Since the reaction occurs slowly, hydrolysis requires the conditions of heat.
The mechanism begins with the protonation of the carbonyl oxygen by the acid catalyst. The protonation makes the amide carbonyl carbon more...
Acid-catalyzed hydrolysis:
Hydrolysis of amides under acidic conditions yields carboxylic acids. Since the reaction occurs slowly, hydrolysis requires the conditions of heat.
The mechanism begins with the protonation of the carbonyl oxygen by the acid catalyst. The protonation makes the amide carbonyl carbon more...
4.5K
01:19Amines to Amides: Acylation of Amines
3.5K
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
3.5K
01:07Acid Halides to Amides: Aminolysis
4.4K
Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
4.4K
01:20Amides to Amines: LiAlH4 Reduction
6.4K
Amide reduction with strong reducing agents like lithium aluminum hydride proceeds through a nucleophilic acyl substitution to form amines. Primary, secondary, and tertiary amides yield primary, secondary, and tertiary amines, respectively.
Amide reduction requires two equivalents of the reducing agent, acting as a source of hydride ions. As shown in the figure, the reaction is initiated with a nucleophilic attack by the hydride ion at the carbonyl carbon to form a tetrahedral intermediate.
Amide reduction requires two equivalents of the reducing agent, acting as a source of hydride ions. As shown in the figure, the reaction is initiated with a nucleophilic attack by the hydride ion at the carbonyl carbon to form a tetrahedral intermediate.
6.4K
01:31Formation of Species
45.5K
Speciation describes the formation of one or more new species from one or sometimes multiple original species. The resulting species are discrete from the parent species, and barriers to reproduction will typically exist. There are two primary mechanisms, speciation with and without geographic isolation—allopatric and sympatric speciation, respectively.
45.5K