铜催化有氧性形C-H氧化,由胺部分指导
Yi-Feng Wang1, Hui Chen, Xu Zhu
1Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Journal of the American Chemical Society
|July 14, 2012
概括
这项研究引入了一种新方法,用于利用铜催化剂和分子氧气在胺基中氧化特定的C-H键. 该过程有效地产生了有价值的异环化合物,如二甲和甲.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 合成方法论 合成方法论
背景情况:
- 在有机合成中,三级C-H键的功能化仍然是一个重大挑战.
- 氨基酸是合成含异环的多功能基石.
研究的目的:
- 开发一种有效的方法,用于直接氧化N-胺和N--2-烯) 胺中的三级C-H键.
- 为了利用大气中的分子氧气作为这种转换的氧气来源.
主要方法:
- 采用一个由铜化物 (CuBr) 和2.2'-双二组成的催化系统.
- 在分子氧气 (O2) 大气下进行反应.
主要成果:
- 在研究的胺基基质中成功氧化了三级C-H键.
- 形成二氧和4H-1,3-氧作为主要产品.
- 将大气中的O2纳入目标分子的演示.
结论:
- 开发的铜催化方法为阿米丁的C-H氧化提供了一条新的途径.
- 这种方法为合成有用的异环化合物提供了一条有效的途径.
- 使用大气中的氧气突出了该过程的可持续性潜力.
相关概念视频
Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
By replacing an α-hydrogen with a halogen, acid-catalyzed α-halogenation of aldehydes or ketones yields a monohalogenated product
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...
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...
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
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 1° Amines: Azide Synthesis
Direct alkylation of ammonia produces polyalkylated amines, along with a quaternary ammonium salt. To exclusively prepare primary amines, the azide synthesis method can be used.
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...

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