D,Lアルファアミノ酸とアリルアミンの合成のための一般的な,高度にエナンチオセレクティブな方法
Young K Chen1, Alice E Lurain, Patrick J Walsh
1P. Roy and Diane T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA.
Journal of the American Chemical Society
|October 10, 2002
まとめ
この研究は,アリルアミン経由でエナチオピュアアミノ酸を合成するための新しい触媒的方法を導入しています. このアプローチは,高収量およびエナチオセレクティブ性を持つ貴重な非タンパク質原性アミノ酸への多用途な経路を提供します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- アシンメトリック・カタリシス
- 合成方法論 合成方法論
背景:
- エナチオセレクティブアミノ酸合成のための伝統的な方法は,範囲の制限があります.
- 非対称な触媒は,エナチオピュア化合物の生成に不可欠である.
研究 の 目的:
- エナチオセレクティブアミノ酸合成のための新しい効率的な触媒経路を開発する.
- 既存の合成戦略の限界を克服するために.
主な方法:
- アルデヒドの触媒的エナンチオセレクティブビニレーションにより,アリルアルコールを形成する.
- オーバーマンの[3,3]-シグマトロピクによるイミダートの再配置により,アリルアミンが得られます.
- アリルアミンの酸化分解により,アミノ酸が生成される.
主要な成果:
- この方法は,アミノ酸を良好な収穫量と優れたエナティオメリック過剰量 (ee's) で提供します.
- 挑戦的なアリルアミンおよび非タンパク質原性アミノ酸の合成が実証されています.
- DとLの両方の構成 (1-アダマンチル) グリシンを合成しました.
結論:
- この新しいアプローチは,多様なエナチオピュアアミノ酸を合成するための汎用的かつ効率的な経路を提供します.
- この方法は,アミノ酸生産における非対称な触媒のツールキットを拡張します.
関連する概念動画
02:27Preparation of Alkynes: Alkylation Reaction
Introduction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
01:07Acid 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...
01:29Preparation 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...
01:28Preparation 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...
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
01:14Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.