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Michael D. Fryzuk

Bio: Michael D. Fryzuk is an academic researcher from University of British Columbia. The author has contributed to research in topics: Ligand & Hydride. The author has an hindex of 53, co-authored 267 publications receiving 9186 citations.


Papers
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Journal ArticleDOI
TL;DR: Biological nitrogen fixation by the nitrogenase enzymes has long been a touchstone for dinitrogen chemists and these metalloenzymes employ transition metal-based catalysts to accelerate the thermodynamically feasible production of ammonia.
Abstract: Biological nitrogen fixation by the nitrogenase enzymes has long been a touchstone for dinitrogen chemists.1,2 Both the enzymatic reduction and protonation of N2 mediated by these metalloenzymes (eq 1)3,4 and the industrial hydrogenation of N2 exemplified by the Haber-Bosch process (eq 2)5-7 employ transition metal-based catalysts to accelerate the thermodynamically feasible production of ammonia.

576 citations

Journal ArticleDOI
TL;DR: A review of the recent literature concerning coordination chemistry and the reactivity patterns of metal-dinitrogen complexes is presented in this article, where the emphasis is on synthesis and reactivity pattern of recently discovered dinitrogen compounds.

401 citations

Journal ArticleDOI
07 Mar 1997-Science
TL;DR: In this article, the reaction of dihydrogen with a side-on bound dinitrogen complex of zirconium was investigated and a complex containing both a bridging hydride and bridging hydrazido unit with a nitrogen-hydrogen bond was observed.
Abstract: The reaction of dihydrogen with a side-on bound dinitrogen complex of zirconium was investigated. Instead of a displacement of the dinitrogen moiety, which is the common mode of reactivity, a complex containing both a bridging hydride and a bridging hydrazido unit with a nitrogen-hydrogen bond was observed. This reaction was extended to primary silanes to produce a species that contained a nitrogen-silicon bond. In addition, an intermediate in the dihydrogen addition has been structurally characterized as having a bridging dihydrogen unit.

343 citations

Journal ArticleDOI
TL;DR: The authors decrit different procedures de synthese de complexes amido du ruthenium, du rhodium, de liridium, du palladium and du platine.

218 citations

Journal ArticleDOI
22 Mar 2017
TL;DR: In this article, the influence of coordination mode on the likelihood of functionalization and the nature of the products, which take the form of nitrogen-containing complexes and organics, as well as species such as NH3 and NH4.
Abstract: Molecular nitrogen (N2) is the most abundant gas in Earth's atmosphere, but its low reactivity has hampered its use as a precursor to higher value nitrogen-containing compounds. Coordination of N2 to metal centres offers a way to overcome this intrinsic inertness and allows the discovery of new transformations. The expanding family of isolable N2 coordination complexes exhibits various bonding modes that, in particular cases, facilitate catalytic or stoichiometric transformations of the N2 unit. In this Review, we survey metal complexes of N2 in order to correlate bonding mode with functionalization propensity. Although many factors influence the functionalization of N2, we propose that coordination mode could be more important than previously recognized. The relative inertness of dinitrogen can be overcome by coordination to suitable organometallics. This Review explores the influence of coordination mode on the likelihood of functionalization and the nature of the products, which take the form of nitrogen-containing complexes and organics, as well as species such as NH3 and N2H4.

201 citations


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TL;DR: The discussion includes an analysis of trends in catalyst activity, a description of catalysts coordinated with N-heterocyclic carbene ligands, and an overview of ongoing work to improve the activity, stability, and selectivity of this family of L2X2Ru=CHR complexes.
Abstract: In recent years, the olefin metathesis reaction has attracted widespread attention as a versatile carbon−carbon bond-forming method. Many new applications have become possible because of major advances in catalyst design. State-of-the-art ruthenium catalysts are not only highly active but also compatible with most functional groups and easy to use. This Account traces the ideas and discoveries that were instrumental in the development of these catalysts, with particular emphasis on (PCy3)2Cl2RuCHPh and its derivatives. The discussion includes an analysis of trends in catalyst activity, a description of catalysts coordinated with N-heterocyclic carbene ligands, and an overview of ongoing work to improve the activity, stability, and selectivity of this family of L2X2RuCHR complexes.

3,229 citations

Journal ArticleDOI
TL;DR: New methods for the synthesis of complexes with N-heterocyclic carbene ligands such as the oxidative addition or the metal atom template controlled cyclized isocyanides have been developed recently.
Abstract: The chemistry of heterocyclic carbenes has experienced a rapid development over the last years. In addition to the imidazolin-2-ylidenes, a large number of cyclic diaminocarbenes with different ring sizes have been described. Aside from diaminocarbenes, P-heterocyclic carbenes, and derivatives with only one, or even no heteroatom within the carbene ring are known. New methods for the synthesis of complexes with N-heterocyclic carbene ligands such as the oxidative addition or the metal atom template controlled cyclization of β-functionalized isocyanides have been developed recently. This review summarizes the new developments regarding the synthesis of N-heterocyclic carbenes and their metal complexes.

2,454 citations

Journal ArticleDOI
30 May 2002-Nature
TL;DR: The recent development of promising catalytic systems highlights the potential of organometallic chemistry for useful C-H bond activation strategies that will ultimately allow us to exploit Earth's alkane resources more efficiently and cleanly as discussed by the authors.
Abstract: The selective transformation of ubiquitous but inert C–H bonds to other functional groups has far-reaching practical implications, ranging from more efficient strategies for fine chemical synthesis to the replacement of current petrochemical feedstocks by less expensive and more readily available alkanes. The past twenty years have seen many examples of C–H bond activation at transition-metal centres, often under remarkably mild conditions and with high selectivity. Although profitable practical applications have not yet been developed, our understanding of how these organometallic reactions occur, and what their inherent advantages and limitations for practical alkane conversion are, has progressed considerably. In fact, the recent development of promising catalytic systems highlights the potential of organometallic chemistry for useful C–H bond activation strategies that will ultimately allow us to exploit Earth's alkane resources more efficiently and cleanly.

2,284 citations

Journal ArticleDOI
TL;DR: The increasing demand to produce enantiomerically pure pharmaceuticals, agrochemicals, flavors, and other fine chemicals has advanced the field of asymmetric catalytic technologies, and asymmetric hydrogenation utilizing molecular hydrogen to reduce prochiral olefins, ketones, and imines has become one of the most efficient methods for constructing chiral compounds.
Abstract: The increasing demand to produce enantiomerically pure pharmaceuticals, agrochemicals, flavors, and other fine chemicals has advanced the field of asymmetric catalytic technologies.1,2 Among all asymmetric catalytic methods, asymmetric hydrogenation utilizing molecular hydrogen to reduce prochiral olefins, ketones, and imines, have become one of the most efficient methods for constructing chiral compounds.3 The development of homogeneous asymmetric hydrogenation was initiated by Knowles4a and Horner4b in the late 1960s, after the discovery of Wilkinson’s homogeneous hydrogenation catalyst [RhCl(PPh3)3]. By replacing triphenylphosphine of the Wilkinson’s catalystwithresolvedchiralmonophosphines,6Knowles and Horner reported the earliest examples of enantioselective hydrogenation, albeit with poor enantioselectivity. Further exploration by Knowles with an improved monophosphine CAMP provided 88% ee in hydrogenation of dehydroamino acids.7 Later, two breakthroughs were made in asymmetric hydrogenation by Kagan and Knowles, respectively. Kagan reported the first bisphosphine ligand, DIOP, for Rhcatalyzed asymmetric hydrogenation.8 The successful application of DIOP resulted in several significant directions for ligand design in asymmetric hydrogenation. Chelating bisphosphorus ligands could lead to superior enantioselectivity compared to monodentate phosphines. Additionally, P-chiral phosphorus ligands were not necessary for achieving high enantioselectivity, and ligands with backbone chirality could also provide excellent ee’s in asymmetric hydrogenation. Furthermore, C2 symmetry was an important structural feature for developing new efficient chiral ligands. Kagan’s seminal work immediately led to the rapid development of chiral bisphosphorus ligands. Knowles made his significant discovery of a C2-symmetric chelating bisphosphine ligand, DIPAMP.9 Due to its high catalytic efficiency in Rh-catalyzed asymmetric hydrogenation of dehydroamino acids, DIPAMP was quickly employed in the industrial production of L-DOPA.10 The success of practical synthesis of L-DOPA via asymmetric hydrogenation constituted a milestone work and for this work Knowles was awarded the Nobel Prize in 2001.3k This work has enlightened chemists to realize * Corresponding author. 3029 Chem. Rev. 2003, 103, 3029−3069

1,995 citations