crosscoupling of terminalalkynes is an efficient chemical process for manufacturing asymmetrical 1,3-conjugated diynes. However, it often occurs in homogenous conditions and costs a lot for reaction treatment. Herein, a copper catalyzed strategy is used to synthesize highly orderedmesoporous nitrogen-doped carbon material (OMNC), and the copper species is in situ transformed into the copper single-atom
1,3-共轭二炔是一类重要的化学中间体,末端炔烃的选择性交叉偶联是制备不对称1,3-共轭二炔的有效化学工艺。然而,它经常发生在均质条件下,反应处理成本很高。本文采用铜催化合成高度有序的介孔氮掺杂碳材料(OMNC),将铜物种原位转化为具有四氮配位的铜单原子位点(CuN 4)。这些特性使 CuN 4/OMNC 催化剂在温和条件 (40 °C) 和低底物比 (1.3) 下有效用于末端炔烃的选择性氧化交叉偶联,以及广泛的不对称和对称 1,3-二炔(26 个实例)。密度泛函理论 (DFT) 计算表明芳基-烷基交叉偶联在 CuN 4位点具有最低的能垒,这可以解释高选择性。此外,催化剂可以通过简单的离心或过滤分离和重复使用。这项工作可以为构建单原子负载的介孔材料以桥接均相和多相催化开辟一条简便的途径。
Copper(I)-Zeolites as New Heterogeneous and Green Catalysts for Organic Synthesis
highly attractive as catalysts for organic chemists, especially with regard to aspects of ‘green chemistry’. 1 Introduction 2 Synthesis and Structures of CuI-Doped Zeolites 3 CuI-Zeolites as Catalysts in Organic Synthesis 3.1 Cycloadditions: ‘Click in Zeo’ 3.2 Cascade Reactions: Substitution and Cycloaddition 3.3 Cycloadditions: Mechanistic Investigations 3.4 Homocoupling of Alkynes 4 Conclusion zeolite
我们已经评估了Cu I掺杂的沸石作为有机合成的非均相催化剂的潜力。事实证明,这种催化剂易于制备,处理,回收和再循环。它们可用于不同的合成应用,例如炔烃与叠氮化物或甲亚胺亚胺的[3 + 2]环加成反应以及炔烃的均相偶联。这些有趣的特性使它们作为有机化学家的催化剂极具吸引力,特别是在“绿色化学”方面。 1引言 2 Cu I掺杂沸石的合成与结构 3 Cu I-沸石在有机合成中的催化作用 3.1 Cycloadditions:“单击Zeo” 3.2级联反应:取代和环加成 3.3环加成:机理研究 3.4炔烃的同质耦合 4。结论 沸石-铜-催化-绿色化学
Gold-Catalyzed Cadiot-Chodkiewicz-type Cross-Coupling of Terminal Alkynes with Alkynyl Hypervalent Iodine Reagents: Highly Selective Synthesis of Unsymmetrical 1,3-Diynes
作者:Xiangdong Li、Xin Xie、Ning Sun、Yuanhong Liu
DOI:10.1002/anie.201702833
日期:2017.6.6
A new and efficient method for the synthesis of unsymmetrical 1,3‐butadiynes by gold‐catalyzed C(sp)–C(sp) cross‐coupling of terminal alkynes with alkynyl hypervalent iodine(III) reagents has been developed. The reaction features high selectivity and efficiency, mild reaction conditions, wide substrate scope, and functional‐group compatibility, and is a highly attractive complement to existing methods
A novel sulfonamide non-classical carbenoid: a mechanistic study for the synthesis of enediynes
作者:Theodore O. P. Hayes、Ben Slater、Richard A. J. Horan、Marc Radigois、Jonathan D. Wilden
DOI:10.1039/c7ob02437a
日期:——
addition of the nucleophile to the unsaturated system to give a key alkenyl lithium species which is stabilised by an intramolecular coordination effect by a sulfonamide oxygen atom. This species can be considered a vinylidene carbenoid given the carbon atom bears both an anion (as a vinyllithium) and a leaving group (the sulfonamide). The intramolecular coordination effect serves to stabilise the vinyllithium
An iron-based catalytic system was developed for the cross-coupling of 1-bromoalkynes with terminalalkynes to selectively generate unsymmetrical 1,3-butadiynes in water under air. It was found that a combination of 1-bromoalkynes derived from less acidicterminalalkynes with more acidic counterparts would greatly enhance yields and selectivity for unsymmetrical 1,3-butadiynes. The reaction was also