A5036558577- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Organometallic Complex Synthesis and Catalysis
- Crystallography and molecular interactions
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Synthetic Organic Chemistry Methods
- Synthesis and characterization of novel inorganic/organometallic compounds
- Catalytic Cross-Coupling Reactions
- Organoboron and organosilicon chemistry
- Asymmetric Hydrogenation and Catalysis
- Carbon dioxide utilization in catalysis
- Coordination Chemistry and Organometallics
- Ferrocene Chemistry and Applications
- Chemical Synthesis and Analysis
- Magnetism in coordination complexes
- Catalytic Alkyne Reactions
- Metal complexes synthesis and properties
- Cyclopropane Reaction Mechanisms
- Chemical Reactions and Isotopes
- Lanthanide and Transition Metal Complexes
- Catalytic C–H Functionalization Methods
- Boron Compounds in Chemistry
- biodegradable polymer synthesis and properties
- Inorganic and Organometallic Chemistry
- Synthesis and Properties of Aromatic Compounds
Technische Universität Braunschweig
2016-2025
Royal Society of Chemistry
2023
Indian Institute of Technology Kanpur
2023
Korea Advanced Institute of Science and Technology
2023
University of British Columbia
2023
University of Bologna
2023
Uppsala University
2023
Hokkaido University
2023
Columbia University
2023
University of Alberta
2023
Relief from frustration: The sterically demanding carbene 1,3-di-tert-butylimidazolin-2-ylidene and B(C6F5)3, a "frustrated" Lewis pair, is viable system for the activation of CO, HH, CH bonds. However, slow rearrangement to an abnormal carbene–borane adduct allows irreversible formation strong BC bond enables this circumvent frustration at expense its activity. Supporting information article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z802705_s.pdf or author....
The preparation of 2-iminoimidazolines 3a–3f has been accomplished by the Staudinger reaction carbenes 1,3-di-tert-butylimidazolin-2-ylidene (1a), 1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene (1b), 1,3-diisopropylimidazolin-2-ylidene (1c), 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (1d), 1,3-bis(2,6-diisopropylphenylimidazolin-2-ylidene (1e) and 1,3,4,5-tetramethylimidazolin-2-ylidene (1f) with trimethylsilyl azide (Me3SiN3) followed desilylation resulting...
It's a game of give and take: Following the successful design strategy for high-oxidation-state alkene metathesis catalysts Schrock type, one most active homogeneous catalyst systems alkyne has been developed. The activity tungsten alkylidyne complex (see picture) stems from use strong electron-donating imidazolin-2-iminato ligand together with electron-withdrawing fluorinated alkoxides.
Ein Weg aus der Frustration: Das "frustrierte" Lewis-Paar dem sterisch anspruchsvollen Carben 1,3-Di-tert-butylimidazolin-2-yliden und B(C6F5)3 eignet sich für die Aktivierung von C-O-, H-H- C-H-Bindungen. Die langsame Umlagerung in ein anomales Carben-Boran-Addukt führt allerdings zur irreversiblen Bildung einer starken B-C-Bindung eröffnet System einen Ausweg Frustration auf Kosten Aktivität. Supporting information for this article is available on the WWW under...
Piggyback ride: Anionic N-heterocyclic carbenes are presented that bear their negative charge in the form of a weakly coordinating anionic borate moiety backbone. This class carbene can be used silver-free routes for preparation neutral, single-source gold(I) catalysts, performance which is comparable with other cationic catalysts enyne rearrangements. Detailed facts importance to specialist readers published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or...
The imidazolin-2-iminato tungsten alkylidyne complexes [Me3CC≡W(NImR)(OR′)2] (4a: R = tBu, R′ CMe3; 4b: Dipp, 5a: CMe(CF3)2; 5b: CMe(CF3)2 have been prepared from [Me3CC≡W(OCMe3)3] (2) and [Me3CC≡W{OCMe(CF3)2}3(dme)] (3, dme 1,2-dimethoxyethane) by reaction with the lithium reagents Li(NImtBu) Li(NImDipp), generated MeLi 1,3-di-tert-butylimidazolin-2-imine (ImtBuNH) or 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-imine (ImDippNH), respectively. Reaction of 3 Li[N(tBu)Ar]·OEt2 (Ar...
The number of well-defined molybdenum and tungsten alkylidyne complexes that are able to catalyze alkyne metathesis reactions efficiently has been significantly expanded in recent years.The latest developments this field featuring highly active imidazolin-2-iminato- silanolate-alkylidyne outlined review.
A series of lithium complexes anionic N-heterocyclic carbenes that contain a weakly coordinating borate moiety (WCA-NHC) was prepared in one step from free by deprotonation with n-butyl followed borane addition. The reaction the resulting lithium-carbene adducts [M(COD)Cl]2 (M = Rh, Ir; COD 1,5-cyclooctadiene) afforded zwitterionic rhodium(I) and iridium(I) type [(WCA-NHC)M(COD)], which metal atoms exhibit an intramolecular interaction N-aryl groups carbene ligands. For M neutral complex...
The rare earth metal dichlorides [(1)MCl2(THF)3] (2a, M = Sc; 2b, Y; 2c, Lu) and the gadolinium complex [(1)GdCl2(THF)2]·[LiCl(THF)2] (2d), containing 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-iminato ligand 1, proved to be versatile starting materials for preparation of trimethylsilylmethyl ("neosilyl") bis(trimethylsilyl)amido complexes [(1)M(CH2SiMe3)2(THF)2] (3a−3d) [(1)M(HMDS)2(THF)] [4a−4d, HMDS hexamethyldisilazide, N(SiMe3)2] benzyl [(1)Lu(CH2Ph)2(THF)2] (5c) by reaction with...
Abstract Tris[3,5‐bis(trifluoromethyl)phenyl]borane reacts with the sterically demanding Arduengo carbenes 1,3‐di‐ tert ‐butylimidazolin‐2‐ylidene and 1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene to form isolable normal adducts. In case of ‐butylimidazolin‐2‐ylidene, adduct exhibits dynamic behaviour in solution frustrated‐Lewis‐pair (FLP) reactivity. Fast cleavage dihydrogen THF, CH activation phenylacetylene, carbon dioxide fixation were achieved by using solutions this benzene....
A variety of Lewis acid-base pairs consisting tris(pentafluorophenyl)borane, B(C(6)F(5))(3), in combination with sterically demanding five- and six-membered N-heterocyclic carbenes (NHCs) the imidazolin-2-ylidene, imidazolidin-2-ylidene, tetrahydropyrimidin-2-ylidene types were investigated respect to their potential act as frustrated (FLP) by reaction dihydrogen (H(2)) tetrahydrofuran (THF). sufficient degree "frustration" was usually established introduction a 1,3-di-tert-butyl or...
Abstract The N‐heterocyclic carbene–phosphinidene adduct IPrPSiMe 3 is introduced as a synthon for the preparation of terminal carbene–phosphinidyne transition metal complexes type [(IPrP)ML n ] (ML =(η 6 ‐p‐cymene)RuCl) and (η 5 ‐C Me )RhCl). Their spectroscopic structural characteristics, namely low‐field 31 P NMR chemical shifts short metal–phosphorus bonds, show their similarity with arylphosphinidene complexes. formally mononegative IPrP ligand also capable bridging two or three...
Abstract The reaction of the 2‐(trimethylsilyl)imidazolium triflate 9 with diarylboron halides (4‐R‐C 6 H 4 ) 2 BX (R=H, X=Br; R=CH 3 , X=Cl; R=CF X=Cl) afforded NHC‐stabilized borenium cations 10 a – c . Cyclic voltammetry revealed linear correlation between Hammett parameter σ p para substituent and half‐wave potential. Chemical reduction decamethylcobaltocene, [(C 5 Me Co], furnished corresponding radicals 11 ; their characterization by EPR spectroscopy confirmed paramagnetic character...
Molybdenum-based molecular alkylidyne complexes of the type [MesC≡Mo{OC(CH3)3–x(CF3)x}3] (MoF0, x = 0; MoF3, 1; MoF6, 2; MoF9, 3; Mes 2,4,6-trimethylphenyl) and their silica-supported analogues are prepared characterized at level, in particular by solid-state NMR, alkyne metathesis catalytic activity is evaluated. The 13C NMR chemical shift carbon increases with increasing number fluorine atoms on alkoxide ligands for both supported catalysts but more shielded values complexes. these order...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA Bis(carbene)-Proton Complex: Structure of a C-H-C Hydrogen BondAnthony J. III Arduengo, Siegfried F. Gamper, Matthias Tamm, Joseph C. Calabrese, Frederic Davidson, and Hugh A. CraigCite this: Am. Chem. Soc. 1995, 117, 1, 572–573Publication Date (Print):January 1995Publication History Published online1 May 2002Published inissue 1 January 1995https://pubs.acs.org/doi/10.1021/ja00106a082https://doi.org/10.1021/ja00106a082research-articleACS...
The reactions and adducts of 1,3,4,5-tetramethylimidazol-2-ylidene with bis(pentamethylcyclopentadienyl)magnesium, -calcium, -strontium, -barium, or -zinc are described. A consistent tend in the spectroscopic properties structures alkaline earth metallocenes is observed. adduct between bis(pentamethylcyclopentadienyl)zinc shows a structure which zinc only σ-bonded to three ligating groups. Among adducts, interaction former carbene center shortest metal−carbon distances each but difference...
The reaction of 1,3-di-tert-butylimidazolin-2-ylidene with trimethylsilyl azide furnishes the corresponding N-silylated 2-iminoimidazoline which reacts titanium(IV) chlorides to yield imidazolin-2-iminato titanium complexes.
The Staudinger reaction of the imidazolin-2-ylidenes, 1,3-di-tert-butylimidazolin-2-ylidene (1a), 1,3-diisopropylimidazolin-2-ylidene (1b), 1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene (1c), 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (1d) and 1,3-bis(2,6-diisopropylphenylimidazolin-2-ylidene (1e), with trimethylsilyl azide furnishes corresponding N-silylated 2-iminoimidazolines 2a–e, which react [(η-C5H5)TiCl3] to afford half-sandwich cyclopentadienyl titanium complexes type...
The reaction of [PhC[triple bond]MBr(3)(dme)] (dme=1,2-dimethoxyethane) with the hexafluoro-tert-butoxides LiX or KX [X=OC(CF(3))(2)Me] afforded benzylidyne complexes bond]MX(3)(dme)] (2a: M=W, 2b: M=Mo), which further reacted lithium reagent Li(Im(tBu)N), generated MeLi from 1,3-di-tert-butylimidazolin-2-imine (Im(tBu)NH), to form imidazolin-2-iminato bond]MX(2)(Im(tBu)N)] (3a: 3b: M=Mo). propylidyne complex [EtC[triple bond]MoX(2)(NIm(tBu))] (4) was obtained by treatment 3b an excess...
This feature article provides an overview of the synthesis and reactivity functionalized cycloheptatrienyl–cyclopentadienyl transition metal sandwich complexes type [(η7-C7H7)M(η5-C5H5)] (M = group 4, 5 or 6 metal), which can be used as building blocks for preparation metallopolymers polymetallic complexes. Emphasis is placed on 16-electron 4 Ti, Zr, Hf) their towards σ-donor/π-acceptor ligands, indicates that these bear a close resemblance to Lewis acidic M+IV Based theoretical...