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Reinhard Schmutzler

Bio: Reinhard Schmutzler is an academic researcher from Braunschweig University of Technology. The author has contributed to research in topics: Trimethylsilyl & Crystal structure. The author has an hindex of 29, co-authored 411 publications receiving 4806 citations. Previous affiliations of Reinhard Schmutzler include Wilmington University & University of Alberta.


Papers
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TL;DR: In this paper, 1,3-diarylimidazolinium chlorides were obtained in a three-step sequence via the diimines and ethylene diamine dihydrochlorides.

822 citations

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TL;DR: In this paper, NMR spectroscopy was used to study the kinetics of the hydrolysis of LiPF6 in the homogeneous solvent system propylene carbonate (PC) and DMC.

279 citations

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TL;DR: In this paper, a C−H insertion product derived from 1,3-dimesityldihydroimidazol-2-ylidene (1) with acetylene, acetonitrile, methyl phenyl sulfone, and chloroform was described.
Abstract: Syntheses and characterizations are described for C−H insertion products derived from 1,3-dimesityldihydroimidazol-2-ylidene (1) with acetylene, acetonitrile, methyl phenyl sulfone, and chloroform. In the reaction with acetylene, both acetylenic H-atoms are reactive so that 1 : 1 and 2 : 1 adducts can be obtained. The acetylene and methyl-phenyl-sulfone adducts are structurally characterized by means of single-crystal X-ray structure determinations. The reactions of 1,3,4,5-tetramethylimidazolidin-2-ylidene (8) with chloroform or chlorodifluoromethane are shown to yield 2-(dihaloalkyl)imidazolium salts that arise from a failure of the intermediate 2-protioimidazolium salt to capture the initially formed halocarbanion.

118 citations

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TL;DR: In this paper, the structure of 12-Pn-6 complexes derived from carbene 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene and phosphorus, arsenic, or antimony pentafluoropnictanide anion is reported.
Abstract: Synthesis, characterization, and solid state X-ray crystallographic structures for 12-Pn-6 complexes derived from carbene 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene and phosphorus, arsenic, or antimony pentafluoride are reported. The adducts show octahedral geometries at the pnictogen centers with C-Pn bond distances of 189.8 (P), 199.9 (As), and 217.5 (Sb) pm. The structures are those of internal zwitterions with imidazolium ion character in the heterocyclic ring and a pentafluoropnictanide anion bonded to C2. Adducts of BF3 with 1,3-dimesitylimidazol-2-ylidene and 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene are also reported for comparison. Although the reactivity of chlorinated and non-chlorinated carbenes varies considerably, the spectroscopic and structural properties of analogous adducts are remarkably similar.

84 citations

Journal ArticleDOI
TL;DR: In this paper, new calix[4]arene-based bisphosphonites, bis-phosphonsites and bis-O-acylphosphites were synthesized and characterized.
Abstract: New calix[4]arene-based bis-phosphonites, bis-phosphites and bis-O-acylphosphites were synthesized and characterized. Treatment of these P-ligands with selected rhodium and platinum precursors led to mononuclear complexes that were satisfactorily characterized. The solid state structure of the dirhodium(I) complex 14 has been determined by X-ray diffraction. The two rhodium centres are bridged by two chloro ligands; one rhodium atom is further coordinated by calix[4]arene phosphorus atoms and the other by cyclooctadiene. The new calix[4]arene P-ligands were tested in the Rh(I) catalyzed hydroformylation of 1-octene. All Rh(I) complexes catalyzed the reaction leading to high chemoselectivity with regard to the formation of aldehydes. Yields and n/iso-selectivities depended on the reaction conditions. Average yields of 80 % and n/iso-ratios of about 1.3 to 1.5 were observed. High yields of aldehydes can be achieved using the methoxy substituted P-ligands at low Rh:ligand ratios. Auf Calix[4]arenen basierende Bis-phosphonite, Bis-phosphite und Bis-O-acyl-phosphite als Liganden in der rhodium(I)-katalysierten Hydroformylierung von 1-Octen Neue auf Calix[4]arenen basierende Bis-phosphonite, Bis-phosphite und Bis-O-acyl-phosphite wurden synthetisiert und charakterisiert. Die Umsetzung dieser Phosphorliganden mit ausgewahlten Rhodium- und Platinvorstufen fuhrte zu mononuklearen Komplexen, die vollstandig charakterisiert wurden. Durch eine Rontgenstrukturanalyse konnte die Struktur des Dirhodium( I)-Komplexes 14 im festen Zustand bestimmt werden. Die beiden Rhodiumzentren sind durch zwei Chlorliganden verbruckt, wobei das eine Rhodiumatom an die Phosphoratome des Calix[4]-arens und das andere Rhodiumatom durch das Cyclooctadien koordiniert ist. Die neuartigen phosphorhaltigen Calix[4]aren-Liganden wurden in der Rhodium(I)-katalysierten Hydroformylierung von 1-Octen getestet. Alle Rh(I)-Komplexe katalysierten die Reaktion bei hoher Chemoselektivitat, bezogen auf die Bildung von Aldehyden. Ausbeuten und n/iso-Selektivitaten waren dabei von den Reaktionsbedingungen abhangig. Durchschnittliche Ausbeuten von 80 % und n/iso-Verhaltnisse von 1.3 bis 1.5 wurden beobachtet. Hohe Ausbeuten an Aldehyden bei geringen Rhodium:Ligand-Verhaltnissen konnten durch den Einsatz von methoxysubstituierten Phosphorliganden erzielt werden.

54 citations


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TL;DR: N-Heterocyclic carbenes have become universal ligands in organometallic and inorganic coordination chemistry as mentioned in this paper, and they not only bind to any transition metal, be it in low or high oxidation states, but also to main group elements such as beryllium, sulfur, and iodine.
Abstract: N-Heterocyclic carbenes have become universal ligands in organometallic and inorganic coordination chemistry. They not only bind to any transition metal, be it in low or high oxidation states, but also to main group elements such as beryllium, sulfur, and iodine. Because of their specific coordination chemistry, N-heterocyclic carbenes both stabilize and activate metal centers in quite different key catalytic steps of organic syntheses, for example, C-H activation, C-C, C-H, C-O, and C-N bond formation. There is now ample evidence that in the new generation of organometallic catalysts the established ligand class of organophosphanes will be supplemented and, in part, replaced by N-heterocyclic carbenes. Over the past few years, this chemistry has been the field of vivid scientific competition, and yielded previously unexpected successes in key areas of homogeneous catalysis. From the work in numerous academic laboratories and in industry, a revolutionary turning point in oraganometallic catalysis is emerging.

3,388 citations

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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

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TL;DR: The fascinating story of olefin (or alkene) metathesis began almost five decades ago, when Anderson and Merckling reported the first carbon-carbon double-bond rearrangement reaction in the titanium-catalyzed polymerization of norbornene.
Abstract: The fascinating story of olefin (or alkene) metathesis (eq 1) began almost five decades ago, when Anderson and Merckling reported the first carbon-carbon double-bond rearrangement reaction in the titanium-catalyzed polymerization of norbornene. Nine years later, Banks and Bailey reported “a new disproportionation reaction . . . in which olefins are converted to homologues of shorter and longer carbon chains...”. In 1967, Calderon and co-workers named this metal-catalyzed redistribution of carbon-carbon double bonds olefin metathesis, from the Greek word “μeτάθeση”, which means change of position. These contributions have since served as the foundation for an amazing research field, and olefin metathesis currently represents a powerful transformation in chemical synthesis, attracting a vast amount of interest both in industry and academia.

1,696 citations

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TL;DR: Sterically encumbered Lewis acid and Lewis base combinations do not undergo the ubiquitous neutralization reaction to form "classical" Lewis acid/Lewis base adducts, but both the unquenched Lewis acidity and basicity of such sterically "frustrated Lewis pairs (FLPs)" is available to carry out unusual reactions.
Abstract: Sterically encumbered Lewis acid and Lewis base combinations do not undergo the ubiquitous neutralization reaction to form "classical" Lewis acid/Lewis base adducts. Rather, both the unquenched Lewis acidity and basicity of such sterically "frustrated Lewis pairs (FLPs)" is available to carry out unusual reactions. Typical examples of frustrated Lewis pairs are inter- or intramolecular combinations of bulky phosphines or amines with strongly electrophilic RB(C(6)F(5))(2) components. Many examples of such frustrated Lewis pairs are able to cleave dihydrogen heterolytically. The resulting H(+)/H(-) pairs (stabilized for example, in the form of the respective phosphonium cation/hydridoborate anion salts) serve as active metal-free catalysts for the hydrogenation of, for example, bulky imines, enamines, or enol ethers. Frustrated Lewis pairs also react with alkenes, aldehydes, and a variety of other small molecules, including carbon dioxide, in cooperative three-component reactions, offering new strategies for synthetic chemistry.

1,621 citations

Journal ArticleDOI
TL;DR: The basics of Pd-NHC chemistry are discussed to understand the peculiarities of these catalysts and a critical discussion on their application in C-C and C-N cross-coupling as well as carbopalladation reactions is given.
Abstract: Palladium-catalyzed C-C and C-N bond-forming reactions are among the most versatile and powerful synthetic methods. For the last 15 years, N-heterocyclic carbenes (NHCs) have enjoyed increasing popularity as ligands in Pd-mediated cross-coupling and related transformations because of their superior performance compared to the more traditional tertiary phosphanes. The strong sigma-electron-donating ability of NHCs renders oxidative insertion even in challenging substrates facile, while their steric bulk and particular topology is responsible for fast reductive elimination. The strong Pd-NHC bonds contribute to the high stability of the active species, even at low ligand/Pd ratios and high temperatures. With a number of commercially available, stable, user-friendly, and powerful NHC-Pd precatalysts, the goal of a universal cross-coupling catalyst is within reach. This Review discusses the basics of Pd-NHC chemistry to understand the peculiarities of these catalysts and then gives a critical discussion on their application in C-C and C-N cross-coupling as well as carbopalladation reactions.

1,471 citations