強いアシルドナーとしてのThio FCMA中間物質:複雑なアミド結合の形成に対する一般的な解決策
Yu Rao1, Xuechen Li, Samuel J Danishefsky
1Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065, USA.
Journal of the American Chemical Society
|August 25, 2009
まとめ
この研究は,厳しい条件なしにアミド結合を生成するための新しい方法を紹介しています. これは,チオ酸とイソニトリルから形成されるチオFCMA中間物質が,この中性アミド結合形成の鍵であることを明らかにします.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 合成化学 合成化学とは
背景:
- アミド結合形成は有機合成において極めて重要です.
- 伝統的な方法は,しばしば厳しい条件を必要とし,基板の範囲と機能群の許容性を制限します.
研究 の 目的:
- 中立条件下でアミド結合形成のための新しい方法論を開発する.
- この変換に関与する活性アシルドナーを特定する.
主な方法:
- チオ酸とイソニトリルとの反応.
- 反応中間物質の特性について.
主要な成果:
- 中性アミド結合形成のための新しい方法が確立されました.
- Thio FCMA の中間物質は,アクティブなアシルドナーとして特定されました.
- この方法論は,アミド結合の形成における効率性を実証した.
結論:
- 開発された方法論は,アミド合成への穏やかで効果的な経路を提供します.
- チオFCMA中間物の役割を理解すると,反応機構の洞察が得られます.
関連する概念動画
Amines to Amides: Acylation of Amines
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 amide...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
Acid Halides to Amides: Aminolysis
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...
Preparation of Amides
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...
Amides to Carboxylic Acids: Hydrolysis
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...
Aldehydes and Ketones with Amines: Imine Formation Mechanism
Imine formation involves the addition of carbonyl compounds to a primary amine. It begins with the generation of carbinolamine through a series of steps involving an initial nucleophilic attack and then several proton transfer reactions. The second part includes the elimination of water, as a leaving group, to give the imine.
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
Preparation of 1° Amines: Gabriel Synthesis
Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...


