NCPピンサーイリジウム複合体によるエタノールによるアルケンの転移水素化:範囲とメカニズム
Yulei Wang1, Zhidao Huang1, Xuebing Leng1
1State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis , Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , China.
Journal of the American Chemical Society
|March 9, 2018
まとめ
この研究は,エタノールを用いてアルケンの転移水素化のための新しいイリジウム触媒を導入する. この触媒は高い効率と選択性を示し 化学合成に より環境にやさしいアプローチを提供しています
科学分野:
- 有機金属化学
- カタリシス
- 有機合成
背景:
- トランスファー水素化 (TH) は重要な合成ツールですが,水素源としてエタノールを使用した活性化されていないアルケンへの適用は依然として困難です.
- 効率的で選択的な触媒システムの開発は,持続可能な化学変換に不可欠です.
- イリジウム複合体は,水素化を含む様々な触媒反応において有望であることが示されている.
研究 の 目的:
- 活性化されていないアルケンのエタノールによる転移水素化のための最初の一般的触媒方法を開発する.
- この変換のための新しいNCP型ピンサーイリジウム複合体を合成し,特徴づけること.
- 開発された触媒システムの基質範囲,化学選択性,およびメカニズム的経路を調査する.
主な方法:
- 新しいベンゾキノリン基のNCP型ピンサーイリジウム複合体 (BQ-NC^O P) IrHClの合成.
- 様々な活性化されていないアルケーンとエタノールを水素源として使用する触媒移転水素化反応.
- C2D5ODを用いた運動同位体効果 (KIE) 測定を含む運動と機械学的研究.
- 反応中間物質と静止状態の分析
主要な成果:
- (BQ-NC^O P) Ir/EtOHシステムは,幅広い非活性アルケーン,ヘテロアレン,および内部アルキンのTHを効率的に触媒化する.
- ケトンとカルボキシル酸の存在下でのアルケンの水素化において,高い化学選択性が観察された.
- 機械学的研究により,単位置換および多位置換アルケンの異なる経路が明らかにされ,異なる触媒の休息状態とKIEが示された.
- エタノール脱水は速度を決定するステップとして特定され,エチルアセテートは唯一の副産物であった.
結論:
- 活性化されていないアルケンのエタノールによる転移水素化のための新しい効率的な触媒系が確立されています.
- 触媒は基板の範囲が広く,優れた化学選択性を示し,有機合成に価値があります.
- アルケンの置換パターンによって根本的なメカニズム的差異が発見され,触媒過程の洞察が得られた.
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