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。
Rhodium-Catalyzed Oxidative Annulation of 2- or 7-Arylindoles with Alkenes/Alkynes Using Molecular Oxygen as the Sole Oxidant Enabled by Quaternary Ammonium Salt
system usingmolecularoxygen as the oxidant for rhodium-catalyzed cross-dehydrogenative coupling remains highly desirable. Herein, rhodium-catalyzed oxidative annulation of 2- or 7-phenyl-1H-indoles with alkenes or alkynes to assemble valuable 6H-isoindolo[2,1-a]indoles, pyrrolo[3,2,1-de]phenanthridines, or indolo[2,1-a]isoquinolines using the atmospheric pressure of air as the sole oxidant enabled
开发一种使用分子氧作为铑催化交叉脱氢偶联的氧化剂的高效催化系统仍然是非常需要的。在此,铑催化的 2- 或 7-苯基-1 H-吲哚与烯烃或炔烃的氧化环化以组装有价值的 6 H-异吲哚[ 2,1 - a ]吲哚、吡咯并[3,2,1- de ]菲啶或吲哚并[2,1- a ]异喹啉使用大气压空气作为唯一氧化剂由季铵盐实现。机理研究为通过添加季铵盐促进了 Rh(I)/Rh(III) 的快速分子内 aza-Michael 反应和有氧再氧化提供了证据。
Rhodium-Catalyzed Oxidative Coupling/Cyclization of 2-Phenylindoles with Alkynes via C−H and N−H Bond Cleavages with Air as the Oxidant
The straightforward and efficient synthesis of indolo[2,1-a]isoquinoline derivatives has been achieved by the rhodium-catalyzed aerobic oxidative coupling/cyclization of 2-phenylindoles with alkynes. Some of the polycyclic products exhibit solid-state fluorescence.
吲哚[ 2,1- a ]异喹啉衍生物的直接有效合成是通过铑催化的2-苯基吲哚与炔烃的需氧氧化偶联/环化而实现的。一些多环产物表现出固态荧光。
Micro-photo-flow reactor system for fused N-heteroaryl scaffold synthesis and late-stage functionalization of pyrazolopyridines
作者:Sanjeev Kumar、Ajay K. Singh
DOI:10.1039/d2cc03713k
日期:——
Late-stage functionalization (LSF) of active pharmaceutical ingredients can provide a straightforward approach to efficient de novo design and synthesis of drug molecules for structural activity relationship studies (SARS). Herein, we have developed a visible-light-driven modular micro-flow reactor consisting of an integrated post-synthetic work-up that was designed and developed to synthesize a fused N-heteroaryl