明確に定義された (POCOP) Rh触媒で,アリルハリドをチオールと結合させる
Samuel D Timpa1, Christopher J Pell, Oleg V Ozerov
1Department of Chemistry, Texas A&M University , College Station, Texas 77842, United States.
Journal of the American Chemical Society
|September 27, 2014
まとめ
新しいピンサー・ロジウム触媒は,アリルハリドとチオルのC-Sクロスカップリング反応を効率的に媒介する. この触媒システムは,低負荷下でも高い収量を示し,結合プロセスに関する機械的洞察を提供します.
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
- 合成化学 合成化学とは
背景:
- クロスカップリング反応は,有機合成の基本です.
- C-S債券形成のための効率的な触媒の開発は,依然として重要な課題です.
- ピンチャー・コンプレックスは,ユニークな安定性と反応性プロファイルを提供します.
研究 の 目的:
- C-Sクロスカップリングのための新しいピンサー・ロジウム触媒を開発する.
- 開発されたシステムの触媒的活動とメカニズム的経路を調査する.
- 性能を既存の触媒システムと比較する.
主な方法:
- (POCOP) Rh前触媒の合成と特徴付け.
- アリルハリドとチオルのC-Sクロスカップリングの触媒試験.
- 鍵となる機械的中間物質の分離と特徴付け.
- 反応依存性を明らかにするための運動学的研究.
主要な成果:
- (POCOP) Rh H Cl) 前触媒は,アリル塩化物およびブロミドをチオール (>90%の収量) と効果的に結合させます.
- 特定の基板では0.1%以下の触媒負荷で高い収量が得られる.
- (POCOP) Rh ((Ph)) ((SPh)) と (POCOP) Rh ((SPh2) のような機械的中間物質を分離し,特徴づけました.
- 触媒処理速度は,アリル塩化物濃度に依存し,オルソ置換ハリドによって阻害されます.
結論:
- (POCOP) Rhピンサーシステムは,C-Sクロスカップリングの非常に効果的な前催化剤です.
- 触媒はアリルチオラートの還元性除去を好み,関連するPNPシステムを上回る.
- 機械学的研究は,触媒サイクルと基板の制限に関する貴重な洞察を提供します.
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