Ruthenium(II)-Catalyzed Regioselective 1,2-Hydrosilylation of <i>N</i>-Heteroarenes and Tetrel Bonding Mechanism
作者:Deepak Behera、Subramanian Thiyagarajan、Puthannur K. Anjalikrishna、Cherumuttathu H. Suresh、Chidambaram Gunanathan
DOI:10.1021/acscatal.1c01148
日期:2021.5.21
to exclusive N-silyl-1,2-dihydroheteroarene products. This catalytic method displays a broad substrate scope; quinolines, isoquinolines, benzimidazoles, quinoxalines, pyrazines, pyrimidines, and pyridines undergo highly selective 1,2-dearomatization. Both electron-donating and electron-withdrawing substituents on N-heteroaromatics are well tolerated in this protocol. Mechanistic studies indicate the
使用钌预催化剂[ Ru- (对-cymene)(PCy 3)Cl 2 ] 1实现了N-杂芳烃的高效区域选择性脱芳香化。反应在温和和纯净的条件下进行。多种N-杂芳烃在预催化剂1的存在下进行硅烷的加成反应,从而形成了独特的N-甲硅烷基-1,2-二氢杂芳烃产品。这种催化方法显示出较宽的底物范围。喹啉,异喹啉,苯并咪唑,喹喔啉,吡嗪,嘧啶和吡啶经历高度选择性的1,2-脱芳香化作用。N上的给电子和吸电子取代基-杂芳族化合物在该方案中具有良好的耐受性。机理研究表明在反应混合物中存在[ Ru- (对-cymene)(PCy 3)HCl] 4,这可能是催化剂的静止状态。密度泛函理论(DFT)研究揭示了完整的催化循环,表明产物的形成受N→Si锡rel键的控制。最初,PCy 3从1上解离,然后[(对-cymene)RuCl 2 ] 20与硅烷进一步反应,生成了催化活性中间体[(p- cymene)RuHCl]