クロミウムコーロールによって触媒化されたエアロビック酸化
Atif Mahammed1, Harry B Gray, Alexandre E Meier-Callahan
1Department of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Journal of the American Chemical Society
|January 30, 2003
まとめ
クロミウム ((V) コロール複合体は,エアロビック酸化反応を触媒化し,基板を製品に変換する. 溶媒の選択は反応速度と触媒の安定性に大きく影響し,全体的な触媒効率に影響します.
科学分野:
- 有機金属化学 有機金属化学
- カタリシス カタリシス カタリシス
- グリーン・ケミストリー (Green Chemistry)
背景:
- コロール複合体は,汎用的な触媒である.
- 酸化反応は化学合成において極めて重要です.
- クロミウム複合体は,ユニークな触媒特性を持っています.
研究 の 目的:
- オキシクロミウム (V) 複合体の触媒的活性を調べる.
- エアロビック酸化のメカニズムを探求するために.
- 触媒性能に対する溶媒効果の役割を理解する.
主な方法:
- クロミウム ((V) コロール複合体の合成.
- トリフェニルフォスフィンやノルボレンンなどの基質のエアロビック酸化.
- 反応中介物質と反応産物のモニタリングのための光譜分析.
- 反応速度と溶媒効果を評価するための運動学的研究.
主要な成果:
- クロミウム ((V) コロール複合体は,基板を効果的に酸素化する.
- 触媒サイクルは,Cr (V) からCr (III) への還元と,Cr (III) の二酸化物による再酸化を含む.
- 重要な溶媒効果が観察されました:アセトニトリルは初期に迅速な転機を誘導し,その後阻害が起こりますが,トロウレン,THF,メタノールは遅い阻害反応を示します.
- アセトニトリルで観察されたCr (IV) 種の形成は,潜在的に触媒の無効化につながる可能性があります.
結論:
- オキシクロミウム ((V) コロール複合体は,活性有酸素酸化触媒である.
- 反応結果と触媒の安定性は,溶媒媒介に大きく依存しています.
- 溶媒効果を理解することは,触媒効率の最適化と,クロム触媒による有酸素酸化における触媒の無効化を防止するために重要である.
関連する概念動画
03:11Oxidation-Reduction Reactions
Oxidation–Reduction Reactions
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
02:37Oxidation of Alcohols
In this lesson, the oxidation of alcohols is discussed in depth. The various reagents used for oxidation of primary and secondary alcohols are detailed, and their mechanism of action is provided.
The process of oxidation in a chemical reaction is observed in any of the three forms:
The process of oxidation in a chemical reaction is observed in any of the three forms:
01:19Oxidation and Reduction of Organic Molecules
Energy production within a cell involves many coordinated chemical pathways. Most of these pathways are combinations of oxidation and reduction reactions, which occur at the same time. An oxidation reaction strips an electron from an atom in a compound, and the addition of this electron to another compound is a reduction reaction. Because oxidation and reduction usually occur together, these pairs of reactions are called redox reactions.
The removal of an electron from a molecule, results in a...
The removal of an electron from a molecule, results in a...
01:17Oxidation of Phenols to Quinones
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
01:19Phase I Oxidative Reactions: Overview
Phase I biotransformation, or functionalization, is a crucial chemical process that converts drugs and other xenobiotics into more water-soluble forms, facilitating expulsion from the body. It involves oxidative, reductive, and hydrolytic reactions that add or unveil polar functional groups on lipophilic substrates. Key players in phase I reactions are the mixed-function oxidases. Situated in liver cell microsomes, these enzymes predominantly carry out drug metabolism. They require molecular...