Cross-metathesis reaction of functionalized and substituted olefins using group 8 transition metal carbene complexes as metathesis catalysts
申请人:CALIFORNIA INSTITUTE OF TECHNOLOGY
公开号:US09403854B2
公开(公告)日:2016-08-02
The invention pertains to the use of Group 8 transition metal carbene complexes as catalysts for olefin cross-metathesis reactions. In particular, ruthenium and osmium alkylidene complexes substituted with an N-heterocyclic carbene ligand are used to catalyze cross-metathesis reactions to provide a variety of substituted and functionalized olefins, including phosphonate-substituted olefins, directly halogenated olefins, 1,1,2-trisubstituted olefins, and quaternary allylic olefins. The invention further provides a method for creating functional diversity using the aforementioned complexes to catalyze cross-metathesis reactions of a first olefinic reactant, which may or may not be substituted with a functional group, with each of a plurality of different olefinic reactants, which may or may not be substituted with functional groups, to give a plurality of structurally distinct olefinic products. The methodology of the invention is also useful in facilitating the stereoselective synthesis of 1,2-disubstituted olefins in the cis configuration.
A General Model for Selectivity in Olefin Cross Metathesis
作者:Arnab K. Chatterjee、Tae-Lim Choi、Daniel P. Sanders、Robert H. Grubbs
DOI:10.1021/ja0214882
日期:2003.9.1
When an olefin of high reactivity is reacted with an olefin of lower reactivity (sterically bulky, electron-deficient, etc.), selective cross metathesis can be achieved using feedstock stoichiometries as low as 1:1. By employing a metathesis catalyst with the appropriate activity, selective cross metathesis reactions can be achieved with a wide variety of electron-rich, electron-deficient, and sterically
近年来,烯烃交叉复分解(CM)已成为有机化学中一种强大而方便的合成技术;然而,作为一种通用的合成方法,CM 受到产品选择性和立体选择性缺乏可预测性的限制。对几类烯烃(包括取代和官能化的苯乙烯、仲烯丙醇、叔烯丙醇和具有 α-季铵盐中心的烯烃)进行烯烃交叉复分解的研究,得出了一个通用模型,可用于预测交叉反应中的产物选择性和立体选择性。复分解。作为 CM 中烯烃反应性的一般排名,烯烃可以根据它们通过交叉复分解进行均二聚化的相对能力和它们的同二聚体对二级复分解反应的敏感性进行分类。当高反应性烯烃与低反应性烯烃(空间体积大、缺电子等)反应时,可以使用低至 1:1 的原料化学计量实现选择性交叉复分解。通过使用具有适当活性的复分解催化剂,可以与多种富电子、缺电子和空间大的烯烃实现选择性交叉复分解反应。该模型的应用允许预测和开发选择性交叉复分解反应,最终形成前所未有的三组分分子间交叉复分解反应。通过使用具
Rhodium-Catalyzed Cyclopropanation of Alkenes with Dimethyl Diazomalonate
作者:Francisco González-Bobes、Michaël D. B. Fenster、Susanne Kiau、Laxma Kolla、Sergei Kolotuchin、Maxime Soumeillant
DOI:10.1002/adsc.200800027
日期:2008.4.7
α′-tetramethyl-1,3-benzenedipropanoate] to catalyze the cyclopropanation of a wide range of alkenes with malonate-derived carbenoids under mild reaction conditions is reported in this communication. The experimental protocol is remarkably simple, uses readily accessible and stable dimethyldiazomalonate with very low catalyst loading. More importantly, the alkene is employed as a limiting reagent.
Co(II) Schiff base complex decorated on polysalicylaldehyde as an efficient, selective, heterogeneous and reusable catalyst for epoxidation of olefins in mild and self-coreductant conditions
new Co(II)-Schiff base complex was decorated on a polysalicylaldehyde (PSA) framework and used as a selective and efficientcatalyst for the epoxidation of alkenes in the presence of O2 as a green source of oxygen without aco-reductant. The catalyst was characterized step by step by FTIR, UV–Vis, 1H NMR, TGA, CHN, XPS and EDX analyses. Loading an amount of Co ions in the catalyst as well as its leaching
摘要 在聚水杨醛(PSA)骨架上装饰了一种新的Co(II)-席夫碱配合物,并在O 2作为绿色氧源而不存在助还原剂的情况下,用作烯烃环氧化的选择性和高效催化剂。通过FTIR,UV-Vis,1逐步表征催化剂1 H NMR,TGA,CHN,XPS和EDX分析。用ICP-OES仪器研究了催化剂中Co离子的负载量及其浸出量。该催化剂以温和,廉价和有效的方案表现出对多种烯烃优异的活性。同样,可以简单地从反应混合物中回收催化剂,并重复使用几次,而没有任何明显的活性损失。通过反应时间筛选反应参数,包括温度,氧气流量,催化剂量和溶剂。进行了包括XPS光谱学在内的催化研究和一些空白实验,以初步了解反应机理。另外,将新型催化剂的反应性评价为周转频率。 图形概要 已经开发了一种新的有效方案,用于在分子氧的作用下,在轻度和自共轭条件下,使用多水杨醛的多相可循环利用的Co(II)-席夫碱配合物对烯烃进行选择性环氧化。
Rhodium-catalyzed selective C–H functionalization of NNN tridentate chelating compounds via a rollover pathway
作者:Seung Youn Hong、Jaesung Kwak、Sukbok Chang
DOI:10.1039/c5cc09960a
日期:——
Reported herein is the first example of a Rh(NHC)-catalyzed selective bis C-H alkylation of NNN tridentate chelatingcompounds in reaction with alkenes. The observed excellent site-selectivity can readily be explained...