scispace - formally typeset
Topic

Metathesis

About: Metathesis is a(n) research topic. Over the lifetime, 9246 publication(s) have been published within this topic receiving 250828 citation(s).

...read more

Papers
More filters

Journal ArticleDOI
13 Aug 1999-Organic Letters
TL;DR: These air- and water-tolerant complexes were shown to exhibit an increased ring-closing metathesis activity at elevated temperature when compared to that of the parent complex 2 and the previously developed complex 3.

...read more

Abstract: A new family of 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene-substituted ruthenium-based complexes 9a−c has been prepared starting from RuCl2(CHPh)(PCy3)2 2. These air- and water-tolerant complexes were shown to exhibit an increased ring-closing metathesis activity at elevated temperature when compared to that of the parent complex 2 and the previously developed complex 3. In many instances the activity of these complexes also rivaled or exceeded that of the alkoxy−imido molybdenum complex 1. Catalyst loadings of as low as 0.05 mol % could be used.

...read more

3,023 citations


Journal ArticleDOI
Abstract: The reactions of RuCl2(PPh3)3 with a number of diazoalkanes were surveyed, and alkylidene transfer to give RuCl2(CHR)(PPh3)2 (R = Me (1), Et (2)) and RuCl2(CH-p-C6H4X)(PPh3)2 (X = H (3), NMe2 (4), OMe (5), Me (6), F (7), Cl (8), NO2 (9)) was observed for alkyl diazoalkanes RCHN2 and various para-substituted aryl diazoalkanes p-C6H4XCHN2. Kinetic studies on the living ring-opening metathesis polymerization (ROMP) of norbornene using complexes 3−9 as catalysts have shown that initiation is in all cases faster than propagation (ki/kp = 9 for 3) and that the electronic effect of X on the metathesis activity of 3−9 is relatively small. Phosphine exchange in 3−9 with tricyclohexylphosphine leads to RuCl2(CH-p-C6H4X)(PCy3)2 10−16, which are efficient catalysts for ROMP of cyclooctene (PDI = 1.51−1.63) and 1,5-cyclooctadiene (PDI = 1.56−1.67). The crystal structure of RuCl2(CH-p-C6H4Cl)(PCy3)2 (15) indicated a distorted square-pyramidal geometry, in which the two phosphines are trans to each other, and the alkyli...

...read more

1,911 citations


Journal ArticleDOI
Robert H. Grubbs1, Sukbok Chang1Institutions (1)
30 Apr 1998-Tetrahedron
Abstract: Recent advances in olefin metathesis, focusing on the areas of ring-closing olefin metathesis (RCM) and cross metathesis, are reviewed. Among numerous complexes which show catalytic activities in olefin metathesis, recently developed well-defined [Mo] and [Ru] catalyst systems have proven to be very efficient and tolerant of many functional groups. Examples of RCM are organized into the areas of medium or macrocyclizations, peptide chemistry, tandem ring-opening/ring-closing reactions, and RCM mediated rearrangements. Variation of substrates such as in polymer bound forms has been discussed. Applications of acyclic metathesis and ring-opening cross metathesis are also included.

...read more

1,845 citations


Journal ArticleDOI
Abstract: Several highly active, recoverable and recyclable Ru-based metathesis catalysts are presented. The crystal structure of Ru complex 5, bearing a 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene and styrenyl ether ligand is disclosed. The heterocyclic ligand significantly enhances the catalytic activity, and the styrenyl ether allows for the easy recovery of the Ru complex. Catalyst 5 promotes ring-closing metathesis (RCM) and the efficient formation of various trisubstituted olefins at ambient temperature in high yield within 2 h; the catalyst is obtained in >95% yield after silica gel chromatography and can be used directly in subsequent reactions. Tetrasubstituted olefins can also be synthesized by RCM reactions catalyzed by 5. In addition, the synthesis and catalytic activities of two dendritic and recyclable Ru-based complexes are disclosed (32 and 33). Examples involving catalytic ring-closing, ring-opening, and cross metatheses are presented where, unlike monomer 5, dendritic 33 can be readily recovered.

...read more

1,679 citations


Journal ArticleDOI
Alois Fürstner1Institutions (1)
01 Sep 2000-Angewandte Chemie
Abstract: The advent of well-defined catalysts for olefin metathesis which combine high activity, durability, and excellent tolerance towards polar functional groups has revolutionized the field. The past decade has seen the rapid embrace of these reagents as tools for advanced organic and polymer chemistry and the success of this development is witnessed by a plethora of elegant applications to the synthesis of natural and nonnatural products. This review article provides an overview of these developments and intends to familiarize the reader with some very recent advances which hold the promise to expand the scope of the reaction even further. Moreover, the positive impact of metathesis on the fundamental logic of retrosynthetic planning is demonstrated by means of typical examples. Finally, it will be shown that metathesis is by no means restricted to alkenes as substrates, and some comments on metathesis reactions following unconventional mechanistic pathways will also be presented.

...read more

1,614 citations


Network Information
Related Topics (5)
Lewis acids and bases

29.5K papers, 631.7K citations

95% related
Alkyne

13.4K papers, 367.9K citations

95% related
Cycloaddition

39.9K papers, 728.7K citations

95% related
Coupling reaction

18.7K papers, 472.2K citations

95% related
Carbene

16.6K papers, 458.3K citations

94% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20222
2021171
2020224
2019227
2018282
2017192

Top Attributes

Show by:

Topic's top 5 most impactful authors

Robert H. Grubbs

281 papers, 38.2K citations

Siegfried Blechert

130 papers, 5.9K citations

Karol Grela

123 papers, 4.9K citations

Amir H. Hoveyda

117 papers, 9.8K citations

Sambasivarao Kotha

111 papers, 1.6K citations