フォトレドックスニッケル触媒C-Sクロスカップリング:メカニズム,運動学,および一般化

Yangzhong Qin¹, Rui Sun¹, Nikolas P Gianoulis¹

¹Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States.

Journal of the American Chemical Society

|January 19, 2021

まとめ

この研究は,光還元素C-Sクロスカップリングの自己持続的なニッケル触媒サイクルを明らかにし,反応効率を高めています. 機械学的洞察は,亜基質の範囲をアリルブロミドに拡張し,アプリケーションを広げた.

科学分野:

有機化学
カタリシス
写真化学

背景:

フォトレドックス媒介のニッケル触媒のクロスカップリングは,炭素ヘテロ原子結合の新たな経路を提供します.
機理学的研究は,反応性中間物質と不明確な経路のために複雑である.

研究の目的:

フォトレドックスニッケル触媒のC-Sクロスカップリングの包括的なメカニズム調査を行う.
反応経路を明らかにし,重要な中間物質を特定し,反応条件を最適化します.

主な方法:

時間分解のトランジント吸収スペクトロスコーピーを使った.
スターン=ヴォルマー quenchingと量子出力測定を使用した.
"in situ"で形成されたピリジニウムヨウ酸化物の役割を調査した.

主要な成果:

生産性のあるNi (I/III) 触媒回路を発見した.
ピリジニウムヨウ酸化物は,Ni ((I) 形成の主要な冷却剤および酸化還元媒介剤として特定された.
クリティカルな中間物質を観察し,そのレートコンスタントを決定した.

結論:

フォトレドックスC-Sクロスカップリングの完全な反応サイクルを確立した.
機械的洞察は反応効率を向上させ,亜基質の範囲をアリルブロミドに拡大させた.
フォトレドックスC-Sクロスカップリング化学の適用範囲を広げました.

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