用化和化对胺酸的化
Takuji Hatakeyama1, Shingo Ito, Masaharu Nakamura
1Department of Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Journal of the American Chemical Society
|October 13, 2005
概括
乙烯酸的化学结构使酸的高效α-化成为可能. 这种反应具有很高的立体化学反转,对于制造光学活性化合物非常有价值.
科学领域:
- 有机化学 有机化学
- 合成化学 合成化学
- 立体化学是一种立体化学.
背景情况:
- 胺是多功能合成中间体.
- 立体选择合成对于制药和精细化学品至关重要.
- 碳化合物的化通常在立体控制中面临挑战.
研究的目的:
- 开发一种新的方法,使用胺酸对子进行alpha-alkylation.
- 为了研究化反应的立体化学结果.
- 评估这种方法在生产光学活性子方面的实用性.
主要方法:
- 从N-2-(N',N'-diethylamino) ethyl imine中制备一个胺.
- 乙胺与初级/二级基化物或初级基化物的反应.
- 介质的水解产生阿尔法基化.
主要成果:
- 反应提供了阿尔法化基的良好至优异的产量.
- 在电友碳中心观察到高水平的立体化学反转.
- 该方法对初级和二级基化物/化物有效.
结论:
- 面粉化學提供了一條有效的通往α-化基的路徑.
- 反应的高立体反转使其适合于不对称合成.
- 这种方法可以应用于生产有价值的光学活性化合物.
相关概念视频
Acid Halides to Carboxylic Acids: Hydrolysis
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
Acid Halides to Esters: Alcoholysis
Alcoholysis is a nucleophilic acyl substitution reaction in which an alcohol functions as a nucleophile. Acid halides react with alcohol to produce esters. The mechanism proceeds in three steps:
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...
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...
Nitriles to Carboxylic Acids: Hydrolysis
Nitriles undergo acid-catalyzed hydrolysis or base-catalyzed hydrolysis to form a carboxylic acid. These reactions proceed via an amide intermediate.
Diazonium Group Substitution: –OH and –H
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.


