Cationic Ruthenium Complexes in Catalysis

Cationic Ruthenium Complexes in Catalysis PDF Author: Stark. Matthew J. (Matthew James)
Publisher:
ISBN:
Category : Electronic books
Languages : en
Pages : 194

Get Book Here

Book Description
With increasing complexity of metal complexes, it is of worthwhile interest to pursue systematic examinations of ligand modifications to study their impact on the reactivity of a catalyst. To that end, this study aimed to understand the effect electron-withdrawing ligands conveyed to catalytic activity in the etherification of propargylic alcohols and related reactions. A number of half-sandwich ruthenium complexes bearing ligands with varying electron–withdrawing properties were synthesized and structurally characterized. Their electronic and structural properties were investigated utilizing X-ray crystallography, revealing that the series of complexes did not vary significantly in structure. The complexes were studied electronically with cyclic voltammetry, which discovered that the coordinated electron-withdrawing ligands resulted in complexes that were more difficult to oxidize and with possibly decreased electron density at the ruthenium center. All complexes showed catalytic activity in the etherification of propargylic alcohols and in the formation of oxygen-containing heterocycles from propargylic alcohols and diketones. Thermal instability offers an explanation as to why some catalyst systems do not perform very well at elevated temperatures. In a separate study, a more stable tridentate ligand was employed as an architecture for further study in this electronic fine-tuning methodology. A new ruthenium complex bearing a tridendate diacetylpyridine ligand was synthesized, characterized, and employed as catalyst in the coupling of carboxylic acids to terminal alkynes to form enol esters with good regioselectivity. Iron offers a number of advantages in transition metal catalysis, as it is inexpensive and relatively non-toxic. Based on preliminary findings from the Bauer laboratory, an in situ catalyst formed through oxidation of ferrocene boronic acid was found to be catalytically active in the etherification of propargylic acetates. Most interestingly, and opposed to all catalytic reactions performed for this study, the ferrocenium cation does not require elevated temperatures and performs well at room temperature.

Cationic Ruthenium Complexes in Catalysis

Cationic Ruthenium Complexes in Catalysis PDF Author: Stark. Matthew J. (Matthew James)
Publisher:
ISBN:
Category : Electronic books
Languages : en
Pages : 194

Get Book Here

Book Description
With increasing complexity of metal complexes, it is of worthwhile interest to pursue systematic examinations of ligand modifications to study their impact on the reactivity of a catalyst. To that end, this study aimed to understand the effect electron-withdrawing ligands conveyed to catalytic activity in the etherification of propargylic alcohols and related reactions. A number of half-sandwich ruthenium complexes bearing ligands with varying electron–withdrawing properties were synthesized and structurally characterized. Their electronic and structural properties were investigated utilizing X-ray crystallography, revealing that the series of complexes did not vary significantly in structure. The complexes were studied electronically with cyclic voltammetry, which discovered that the coordinated electron-withdrawing ligands resulted in complexes that were more difficult to oxidize and with possibly decreased electron density at the ruthenium center. All complexes showed catalytic activity in the etherification of propargylic alcohols and in the formation of oxygen-containing heterocycles from propargylic alcohols and diketones. Thermal instability offers an explanation as to why some catalyst systems do not perform very well at elevated temperatures. In a separate study, a more stable tridentate ligand was employed as an architecture for further study in this electronic fine-tuning methodology. A new ruthenium complex bearing a tridendate diacetylpyridine ligand was synthesized, characterized, and employed as catalyst in the coupling of carboxylic acids to terminal alkynes to form enol esters with good regioselectivity. Iron offers a number of advantages in transition metal catalysis, as it is inexpensive and relatively non-toxic. Based on preliminary findings from the Bauer laboratory, an in situ catalyst formed through oxidation of ferrocene boronic acid was found to be catalytically active in the etherification of propargylic acetates. Most interestingly, and opposed to all catalytic reactions performed for this study, the ferrocenium cation does not require elevated temperatures and performs well at room temperature.

Half-sandwich Complexes of Ruthenium ; Synthesis and Application to Catalysis

Half-sandwich Complexes of Ruthenium ; Synthesis and Application to Catalysis PDF Author: Sun Hwa Lee
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description


Ruthenium in Catalysis

Ruthenium in Catalysis PDF Author: Pierre H. Dixneuf
Publisher: Springer
ISBN: 3319084828
Category : Science
Languages : en
Pages : 404

Get Book Here

Book Description
The series Topics in Organometallic Chemistry presents critical overviews of research results in organometallic chemistry. As our understanding of organometallic structure, properties and mechanisms increases, new ways are opened for the design of organometallic compounds and reactions tailored to the needs of such diverse areas as organic synthesis, medical research, biology and materials science. Thus the scope of coverage includes a broad range of topics in pure and applied organometallic chemistry, where new breakthroughs are being achieved that are of significance to a larger scientific audience. The individual volumes of Topics in Organometallic Chemistry are thematic. Review articles are generally invited by the volume editors.

Ruthenium Oxidation Complexes

Ruthenium Oxidation Complexes PDF Author: William P. Griffith
Publisher: Springer Science & Business Media
ISBN: 1402093780
Category : Science
Languages : en
Pages : 274

Get Book Here

Book Description
Ruthenium Oxidation Complexes explores ruthenium complexes, particularly those in higher oxidation states, which function as useful and selective organic oxidation catalysts. Particular emphasis is placed on those systems which are of industrial significance. The preparation, properties and applications of the ruthenium complexes are described, followed by a presentation of their oxidative properties and summary of the different mechanisms involved in the organic oxidations (e.g. oxidations of alcohols, alkenes, arenes and alkynes, alkanes, amines, ethers, phopshines and miscellaneous substrates). Moreover, future trends and developments in the area are discussed. This monograph is aimed at inorganic, organic, industrial and catalysis chemists, especially those who wish to carry out specific organic oxidations using catalytic methods.

Synthesis and Structure of a Cationic Ruthenium(II) Complex and It's Catalytic Activity Towards Transfer Hydrogenation of Aldehydes and Ketones

Synthesis and Structure of a Cationic Ruthenium(II) Complex and It's Catalytic Activity Towards Transfer Hydrogenation of Aldehydes and Ketones PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 21

Get Book Here

Book Description
A new cationic ruthenium(II) complex, [Ru(PPh 3 )(CH 3 CN) 2 LCl]Cl·5CHCl3 {L = N-(diphenylphosphino)pyridin-2-amine} has been synthesized and structurally characterized. The complex is an efficient catalyst for the transfer hydrogenation aldehydes and ketones. It can catalyze intramolecular transfer hydrogenation.

Ruthenium

Ruthenium PDF Author: Hitoshi Ishida
Publisher: BoD – Books on Demand
ISBN: 1839629169
Category : Technology & Engineering
Languages : en
Pages : 228

Get Book Here

Book Description
Ruthenium is a precious metal not widely known to non-scientists. It is a target of much research, however. It is used in computer hard drives, the tips of fountain pens, and as a catalyst to purify car exhaust, among other uses. This book presents information and research on the properties and applications of ruthenium, including potential uses in phytochemical functions and anticancer activity.

Half-sandwich Complexes of Ruthenium Supported by N-Heterocyclic Carbene Ligands

Half-sandwich Complexes of Ruthenium Supported by N-Heterocyclic Carbene Ligands PDF Author: Van Hung Mai
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
This thesis presents the preparation and catalytic reactivity of novel half-sandwich ruthenium complexes supported by N-Heterocyclic Carbene (NHC) ligands. The cationic half-sandwich ruthenium complexes [Cp(IPr)Ru(CH3CN)2]+ show interesting reactivities toward the transfer hydrogenation of different unsaturated substrates, such as ketones, olefins, N-heterocycles, and nitriles. Kinetic studies disclose that a neutral trishydride ruthenium complex is actually involved in the catalytic cycle, playing the role as a resting state. Further investigations on the sub-class of trishydride ruthenium complexes bearing NHC ligands (Cp'(NHC)RuH3) reveal that these complexes have an unusual and great catalytic performance toward the hydrodefluorination (HDF) of fluorinated aromatic and aliphatic compounds. The combined kinetic studies, cross-over experiments and rate law analysis suggest an unusual mechanistic pathway for the Cp*(IPr)RuH3 catalyzed HDF. This study is one of the rare examples where isopropanol is employed as a reducing agent for the metal-mediated HDF reaction. A class of silyl dihydride ruthenium complexes, derived from Cp(IPr)RuH3 are prepared. These silyl hydrido derivatives are great compounds for the study of the inter ligand hypervalent interaction (IHI), an interesting phenomenon for many non-classical silane complexes. This study also suggests that the replacement of phosphines by their isolobally analogous NHC ligands result in stronger IHI interactions in the corresponding compounds. Another type of non-classical interaction was systematically scrutinized in a ii series of new cationic and neutral silane sigma complexes of ruthenium bearing different silyl moieties. These new NHC-supported ruthenium complexes allow for direct comparation with the known phosphine analogues, which reveals interplay of steric and electronic factors on the extent of Si-H complexation to metal and the extent of additional interligand interactions between Ru-Cl and chlorosilane ligand. Finally, new trishydride ruthenium complexes bearing NHC ligands (Cp'(NHC)RuH3) catalyze the H/D exchange reaction of various N-heterocycle substrates; their catalytic performance can be considered as one of the mildest, and most efficient approaches.

Ruthenium Catalysts and Fine Chemistry

Ruthenium Catalysts and Fine Chemistry PDF Author: Christian Bruneau
Publisher: Springer Science & Business Media
ISBN: 9783540205432
Category : Science
Languages : en
Pages : 368

Get Book Here

Book Description
With contributions by numerous experts

Half-sandwich Silane Complexes of Ruthenium and Iron

Half-sandwich Silane Complexes of Ruthenium and Iron PDF Author: Dmitry V. Gutsulyak
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description


Metal Vinylidenes and Allenylidenes in Catalysis

Metal Vinylidenes and Allenylidenes in Catalysis PDF Author: Christian Bruneau
Publisher: John Wiley & Sons
ISBN: 9783527318926
Category : Science
Languages : en
Pages : 360

Get Book Here

Book Description
Focusing on preparation and applications in synthesis and catalysis, this book finally closes a gap in the literature by summarizing this hot topic for the first time. As such, it gathers in one volume the key features of metal vinylidene and allenylidene complexes as well as reactive species and covers applications in metathesis, polymerization, molecular materials, carbon rich compounds and fine chemical production. The emphasis here is on the selective transformations of alkynes and enynes plus simple and complex molecules containing a triple C-C bond. The result is a must-have ready reference for organic, catalytic, complex, theoretical and polymer chemists, as well as those working with/on organometallics.