Cobalt-Catalyzed<i>ortho</i>-C−H Functionalization/Alkyne Annulation of Benzylamine Derivatives: Access to Dihydroisoquinolines
作者:Ángel Manu Martínez、Nuria Rodríguez、Ramón Gómez-Arrayás、Juan C. Carretero
DOI:10.1002/chem.201702283
日期:2017.8.25
A practical picolinamide-directed C−H functionalization/alkyne annulation of benzylaminederivatives enabling access to the previously elusive 1,4-dihydroisoquinoline skeleton was developed using molecular O2 as the sole oxidant and Co(OAc)2 as precatalyst. The method is compatible with both internal and terminal alkynes and shows high versatility and functional-group tolerance. Furthermore, full preservation
A Simple Preparation of Amides from Acids and Amines by Heating of Their Mixture
作者:Branko S. Jursic、Zoran Zdravkovski
DOI:10.1080/00397919308013807
日期:1993.11
Abstract Heating a mixture of an amine and an acid is demonstrated as the method of choice for the preparation of many amides. The yields depend on the physical properties and thermal stability of the reactants and range from good to excellent. The ideal reactants should have melting points below 200 °C, should not be highly volatile and should be thermally stable at that temperature for 30 minutes
摘要 加热胺和酸的混合物被证明是制备许多酰胺的首选方法。产率取决于反应物的物理性质和热稳定性,范围从良好到极好。理想的反应物应具有低于 200 °C 的熔点,不应具有高度挥发性,并且应在该温度下热稳定 30 分钟。通过在反应中使用酸酯代替酸可以克服这些缺点中的一些。该方法以其简单、低成本和反应时间短而脱颖而出。它也可以非常大规模地进行,不需要溶剂和反应物的特殊纯化。
Traceless Directing Group Assisted Cobalt-Catalyzed C−H Carbonylation of Benzylamines
作者:Fei Ling、Chongren Ai、Yaping Lv、Weihui Zhong
DOI:10.1002/adsc.201700780
日期:2017.11.10
The first example of cobalt‐catalyzed C(sp2)−H carbonylation of benzylamines using a traceless directing group is reported, which was successfully applied to the synthesis of N−unprotected iso‐indolinones through direct C−H/N−H bonds activation. This protocol tolerates a variety of functional groups and provides a facile and efficient method for the formal synthesis of (+)‐garenoxacin.
报道了使用无痕导向基团的钴催化苄胺的C(sp 2)-H羰基羰基化的第一个实例,该实例已成功地用于通过直接CH / H / NH键活化而合成N-未保护的异吲哚啉酮。该方案可耐受多种官能团,并为(+)-加仑沙星的正式合成提供了一种简便而有效的方法。
Manganese(II/III/I)-Catalyzed C–H Arylations in Continuous Flow
作者:Cuiju Zhu、João C. A. Oliveira、Zhigao Shen、Huawen Huang、Lutz Ackermann
DOI:10.1021/acscatal.8b00166
日期:2018.5.4
Versatile manganese-catalyzed C–H arylations on synthetically meaningful pyridines were accomplished with sustainable MnCl2 as the catalyst. The oxidative C–H functionalizations proved viable with a user-friendly and safe continuous flow setup by weak amide-assisted C–H cleavage via a facile C–H activation regime.
Low-valent manganese-catalyzed C–H alkylation of pyridine derivatives with both primary and challenging secondary alkylhalides was established by amide assistance. The strategy provided expedient access to alkylated pyridines with wide functional group tolerance and ample scope through weak chelation. Mechanistic studies provided strong support for a rate-determining C–H activation and a SET-type