Nickel-catalyzed oxidative C–H/N–H annulation of <i>N</i>-heteroaromatic compounds with alkynes
作者:Atsushi Obata、Akane Sasagawa、Ken Yamazaki、Yusuke Ano、Naoto Chatani
DOI:10.1039/c8sc05063e
日期:——
The reaction of N-heteroaromatic compounds, such as 2-aryl-pyrrole, benzimidazole, imidazole, indole, and pyrazole derivatives, with alkynes in the presence of a catalytic amount of a nickel complex results in C–H/N–H oxidative annulation. The reaction shows a high functional group compatibility. While both Ni(0) and Ni(II) complexes show a high catalytic activity, Ni(0) is proposed as a key catalytic
N-杂芳族化合物(例如 2-芳基吡咯、苯并咪唑、咪唑、吲哚和吡唑衍生物)与炔烃在催化量的镍配合物存在下发生反应,导致 C-H/N-H 氧化成环。该反应表现出较高的官能团相容性。虽然Ni(0)和Ni( II )配合物均表现出高催化活性,但Ni(0)被认为是主催化循环中的关键催化物种。在 Ni( II ) 体系的情况下,反应的进行需要催化量的强碱(例如 KOBu t )的存在。与此形成鲜明对比的是,Ni(0) 系统不需要碱。所提出的机制得到了 DFT 研究的支持。