Formation of CCbonds from CO2 is a much sought after reaction in organic synthesis. To date, other than CH carboxylations using stoichiometric amounts of metals, base, or organometallic reagents, little is known about CC bond formation. In fact, to the best of our knowledge no catalyticmethylation of CHbondsusing CO2 and H2 has been reported. Described herein is the combination of CO2 and H2 for efficient
由CO 2形成CC键是有机合成中非常需要的反应。迄今为止,除了使用化学计算量的金属,碱或有机金属试剂进行的CH羧化反应外,对CC键的形成知之甚少。实际上,据我们所知,没有报道使用CO 2和H 2催化CH键的甲基化。本文描述的是CO 2和H 2的组合,用于碳亲核试剂(如吲哚,吡咯和富电子芳烃)的有效甲基化。使用低聚甲醛的对比实验显示出与CO 2相似的反应性/ H 2系统。
Rhodium(III)-Catalyzed Indole Synthesis Using N–N Bond as an Internal Oxidant
We report herein a Rh(III)-catalyzed cyclization of N-nitrosoanilines with alkynes for streamlined synthesis of indoles. The synthetic protocol features a distinct internal oxidant, N-N bond, as a reactive handle for catalyst turnover, as well as a hitherto tantalizingly elusive intermolecular redox-neutral manifold, predicated upon C-H activation, for the formation of a five-membered azaheterocycle
A versatile, traceless C–H activation-based approach for the synthesis of diversified heterocycles is reported. Rh(III)-catalyzed, N-amino-directed C–H alkenylation generates either olefination products or indoles (in situ annulation) in an atom- and step-economic manner at room temperature. The remarkable reactivity endowed by this directing group enables scale-up of the reaction to a 10 g scale at
A previously elusive RuII‐catalyzed N−N bond‐based traceless C−H functionalization strategy is reported. An N‐amino (i.e., hydrazine) group is used for the directed C−H functionalization with either an alkyne or an alkene, affording an indole derivative or olefination product. The synthesis features a broad substrate scope, superior atom and step economy, as well as mild reaction conditions.
Rhodium-Catalyzed Annulation of Tertiary Aniline <i>N</i>-Oxides to <i>N</i>-Alkylindoles: Regioselective C–H Activation, Oxygen-Atom Transfer, and <i>N</i>-Dealkylative Cyclization
作者:Bin Li、Hong Xu、Huanan Wang、Baiquan Wang
DOI:10.1021/acscatal.6b00311
日期:2016.6.3
[Cp*RhIII]-catalyzed annulation of tertiary aniline N-oxides with alkynes was reported to achieve the challenging ortho C–Hfunctionalization of tertiary anilines via N–O bond acting as a traceless directing group. More significantly, this system represents the first example which integrates C–H activation, oxygen-atom transfer, and N-dealkylative cyclization in one reaction. This unprecedented coupling
据报道,[Cp * Rh III ]催化炔烃与叔胺N-氧化物的环化反应是通过N-O键作为无痕导向基团实现的,具有挑战性的叔苯胺邻位C-H功能化。更重要的是,该系统代表了第一个示例,该示例在一个反应中集成了C–H活化,氧原子转移和N-脱烷基环化。这种空前的偶联反应使N-烷基吲哚衍生物的构建具有高效率,宽泛的底物范围和良好的官能团耐受性。