Copper-Mediated Synthesis of Substituted 2-Aryl-N-benzylbenzimidazoles and 2-Arylbenzoxazoles via C–H Functionalization/C–N/C–O Bond Formation
摘要:
An efficient method for the transformation of N-benzyl bisarylhydrazones and bisaryloxime ethers to functionalized 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles is described. The protocol involves a copper(II)-mediated cascade C-H functionalization/C-N/C-O bond formation under neutral conditions. Substrates having either electron-donating or -withdrawing substituents undergo the cyclization to afford the target heterocycles at moderate temperature.
To expand the toolbox for the synthesis of ortho-phenolic sulfilimines, sigmatropic rearrangements were introduced to the field of sulfiliminechemistry. Herein we report a N-H sulfenylation/[2,3]-sigmatropic rearrangement cascade reaction. This mild reaction enables commercially available thiols to serve as the sulfenylation reagent and generates water as the sole byproduct. Moreover, the reaction
Rhodium(III)-Catalyzed Redox-Neutral Coupling of<i>N</i>-Phenoxyacetamides and Alkynes with Tunable Selectivity
作者:Guixia Liu、Yangyang Shen、Zhi Zhou、Xiyan Lu
DOI:10.1002/anie.201300881
日期:2013.6.3
Give it a tweak: A novel oxidizing directing group was developed for a rhodium(III)‐catalyzed CH functionalization of N‐phenoxyacetamides with alkynes. A small change in the reaction conditions leads to either ortho‐hydroxyphenyl‐substituted enamides or cyclization to deliver benzofurans with high selectivity (see scheme; Cp*=C5Me5).
给它一个调整:一种新颖的氧化定向基团被用于铑(III)催化的开发Ç h的官能Ñ与炔-phenoxyacetamides。反应条件的微小变化会导致邻-羟苯基取代的酰胺或环化反应以高选择性提供苯并呋喃(参见方案; Cp * = C 5 Me 5)。
Rhodium(<scp>iii</scp>)-catalyzed C–H activation/[4+3] annulation of N-phenoxyacetamides and α,β-unsaturated aldehydes: an efficient route to 1,2-oxazepines at room temperature
Formation of C(sp2)–X bonds was carried out using a Fe3O4@SiO2‐copper(I) sucrose xanthate nanoparticle catalyst with the aid of the copper(I) xanthate moiety in the catalyst which was prepared from the reaction between sucrose and carbon disulfide through an alkaline medium via the traditional Zeise approach. Various techniques were employed for the characterization of these novel nanoparticles. Three
C(sp 2)–X键的形成是利用Fe 3 O 4 @SiO 2-铜(I)蔗糖黄原酸酯纳米颗粒催化剂,借助由该催化剂制备的催化剂中的黄原酸铜(I)部分进行的。传统的Zeise方法通过碱性介质使蔗糖和二硫化碳之间发生反应。各种技术被用于表征这些新颖的纳米颗粒。三种杂原子N,O和S成功地进行了杂原子芳基化反应,分别生成仲胺或叔胺,醚和硫醚。
Cobalt(III)‐Catalyzed Enantioselective Intermolecular Carboamination by C−H Functionalization
High‐valent cyclopentadienyl cobalt catalysis is a versatile tool for sustainable C−H bond functionalizations. To harness the full potential of this strategy, control of the stereoselectivity of these processes is necessary. Herein, we report highly enantioselective intermolecular carboaminations of alkenes through C−H activation of N‐phenoxyamides catalyzed by CoIII‐complexes equipped with chiral
高价的环戊二烯基钴催化是实现可持续CH键功能化的通用工具。为了充分利用这种策略的潜力,必须控制这些过程的立体选择性。在本文中,我们报道了通过配备有手性环戊二烯基(Cp x)配体的Co III络合物催化的N苯氧酰胺的C H活化,对烯烃进行高度对映选择性的分子间碳胺化反应。该方法可在非常温和的条件下将广泛使用的丙烯酸酯以及双环烯烃转化为有吸引力的对映体富集的异酪氨酸衍生物,以及经过精制的氨基取代的双环支架。概述的反应性是Cp x Co III特有的 与4d和5d贵金属催化剂的反应性互补。