From a decomposition product to an efficient and versatile catalyst: the [Ru(η5-indenyl)(PPh3)2Cl] story.
From a decomposition product to an efficient and versatile catalyst: the [Ru(η5-indenyl)(PPh3)2Cl] story.
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DOI：
10.1021/ar500225j
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发表时间：
2014-10-21
影响因子：
18.3
通讯作者：
Nolan SP
中科院分区：
文献类型：
--
作者：
Manzini S;Fernández-Salas JA;Nolan SP
催化剂设计中最重要的挑战之一是在不影响其活性的情况下合成稳定的促进剂。因此，了解导致这类催化剂分解的因素是很重要的，特别是当副产物对起始配合物的活性和选择性产生负面影响时。在此背景下，对烯烃复分解终止和分解过程的理解正受到科学界的极大关注。例如，烯烃钌分解预催化剂在醇溶液中的分解既可以发生在催化剂合成过程中，也可以发生在催化过程中，这种分解已被发现在grubbs型预催化剂中很常见。这些分解产物通常是羟基羰基配合物，众所周知，它在氢化、末端烯烃异构化和C-H活化化学等几种转化中都很活跃。这些副产物的反应活性可能是不需要的，因此了解如何避免它们是很重要的，也许保持开放的心态也很重要，并考虑在其他催化反应中使用它们的方法。本帐户报告了这些分解研究的展示。这些报告分析了钌苯乙烯配合物，高活性烯烃复分解预催化剂，在碱性醇溶液中的稳定性。在这些条件下，根据起始络合物和所用的醇，可能发生几种不同的分解过程。这些含独立烷基的复分解配合物表现出与其他复分解预催化剂完全不同的行为，并表现出一种替代的竞争性醇解途径，在这种途径中，独立烷基片段不是形成预期的羟基羰基配合物，而是转化为η - 1-独立基，然后重新排列为η - 5-独立基形式。特别是，[RuCl(η5-(3-苯基lindenylidene)(PPh3)2]已被发现在许多转化（至少20）中非常活跃，并且与广泛的反应条件兼容，使其成为一种多功能的催化工具。应该指出的是，η - 5-苯基独立基配体在相关的半夹层钌配合物上表现出增强的催化活性。类似的半夹心（环戊二烯基和茚二基）钌配合物在转移加氢和烯丙醇异构化反应中表现出较低的活性。此外，这种催化剂还可以获得新的苯乙烯基钌配合物，这种配合物可以以非常直接的方式实现，并已成功地用于催化。这个帐户提供了如何的机制见解分解和稳定性的一个著名的家族钌分解预催化剂导致了一系列新的和多功能的钌配合物与意想不到的反应性的概述。
One of the most important challenges in catalyst design is the synthesis of stable promoters without compromising their activity. For this reason, it is important to understand the factors leading to decomposition of such catalysts, especially if side-products negatively affect the activity and selectivity of the starting complex. In this context, the understanding of termination and decomposition processes in olefin metathesis is receiving significant attention from the scientific community. For example, the decomposition of ruthenium olefin metathesis precatalysts in alcohol solutions can occur during either the catalyst synthesis or the metathesis process, and such decomposition has been found to be common for Grubbs-type precatalysts. These decomposition products are usually hydridocarbonyl complexes, which are well-known to be active in several transformations such as hydrogenation, terminal alkene isomerization, and C–H activation chemistry. The reactivity of these side products can be unwanted, and it is therefore important to understand how to avoid them and maybe also important to keep an open mind and think of ways to use these in other catalytic reactions. A showcase of these decomposition studies is reported in this Account. These reports analyze the stability of ruthenium phenylindenylidene complexes, highly active olefin metathesis precatalysts, in basic alcohol solutions. Several different decomposition processes can occur under these conditions depending on the starting complex and the alcohol used. These indenylidene-bearing metathesis complexes display a completely different behavior compared with that of other metathesis precatalysts and show an alternative competitive alcoholysis pathway, where rather than forming the expected hydrido carbonyl complexes, the indenylidene fragment is transformed into a η1-indenyl, which then rearranges to its η5-indenyl form. In particular, [RuCl(η5-(3-phenylindenylidene)(PPh3)2] has been found to be extremely active in numerous transformations (at least 20) as well as compatible with a broad range of reaction conditions, rendering it a versatile catalytic tool. It should be stated that the η5-phenyl indenyl ligand shows enhanced catalytic activity over related half-sandwich ruthenium complexes. The analogous half-sandwich (cyclopentadienyl and indenyl) ruthenium complexes show lower activity in transfer hydrogenation and allylic alcohol isomerization reactions. In addition, this catalyst allows access to new phenylindenyl ruthenium complexes, which can be achieved in a very straightforward manner and have been successfully used in catalysis. This Account provides an overview of how mechanistic insights into decomposition and stability of a well-known family of ruthenium metathesis precatalysts has resulted in a series of novel and versatile ruthenium complexes with unexpected reactivity.
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影响因子：
4.9
作者：
Das, Shoubhik;Li, Yuehui;Beller, Matthias
通讯作者：
Beller, Matthias
DOI：
10.1039/c39880000278
发表时间：
1988-02-15
影响因子：
--
作者：
CAMPION, BK;HEYN, RH;TILLEY, TD
通讯作者：
TILLEY, TD
影响因子：
1.6
作者：
Bellemin-Laponnaz, S;Le Ny, JP
通讯作者：
Le Ny, JP
影响因子：
2.3
作者：
Dinger, MB;Mol, JC
通讯作者：
Mol, JC
影响因子：
16.6
作者：
Donohoe, Timothy J.;O'Riordan, Timothy J. C.;Rosa, Carla P.
通讯作者：
Rosa, Carla P.