The terphspan scaffold was employed to support a bis(N-heterocyclic carbene) ligand () that provides a m-terphenyl canopy over one side of its metal complexes. Single-crystal X-ray diffraction studies on a silver complex of {[Ag()]AgBr(2)}(2) revealed an unusual tetranuclear silver core with a Ag-Ag bond distance of 3.0241(8) A with as a trans-chelating ligand (C-Ag-C = 171 degrees ). A preliminary X-ray structure of pseudo-square planar [PdCl(2)()] showed a similar binding mode of (C-Pd-C = 177 degrees ). High yields were obtained in Suzuki-Miyaura coupling reactions utilizing [PdCl(2)()] as the procatalyst and the results were compared with analogous complexes of trans-spanning diphosphine () and diphosphinite () complexes. The diphosphinite complex, [PdCl(2)()], decomposes to [mu-ClPd(PPh(2)OH)(PPh(2)O)](2) at room temperature.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/b815739a | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Three-component diels-alder reaction through palladium carbene migratory insertion enabled dearomative C(sp)-H bond activation.
Nat Commun
December 2024
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education of China, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, 410081, China.
Owning to the versatile nature in participation of Diels-Alder (D-A) reactions, the development of efficient approaches to generate active ortho-quinodimethanes (o-QDMs) has gained much attention. However, a catalytic method involving coupling of two readily accessible components to construct o-QDMs is lacking. Herein, we describe a palladium carbene migratory insertion enabled dearomative C(sp)-H activation to form active o-QDM species through the cross-coupling of N-tosylhydrazones with aryl halides.
View Article and Find Full Text PDFFacile and Regioselective Deuteration of C2-Alkylated Imidazolium Salts in the Presence of Cesium Carbonate.
Chemistry
December 2024
Université de Liège: Universite de Liege, Laboratory of Organometallic Chemistry and Homogeneous Catalysis, Institut de chimie B6a, Sart-Tilman, 4000, Liege, BELGIUM.
Thirteen imidazolium iodides bearing benzyl, mesityl, or 2,6-diiso-propyl-phenyl substituents on their nitrogen atoms, and C1 to C4 alkyl chains on their C2 carbon atom were readily deuterated with D2O as a cheap and non-toxic deuterium source in the presence of Cs2CO3, a weak, innocuous, inorganic base. The isotopic exchange proceeded quickly and efficiently under mild, aerobic conditions to afford a range of aNHC and NHO precursors regioselectively labeled on their C2α exocyclic position and/or C4=C5 heterocyclic backbone. A "carbene-free" mechanism was postulated, in which the carbonate anion acts as a catalyst to activate an exocyclic, acidic C-H bond and ease a deuterium transfer from D2O to the imidazolium salt in a concerted fashion.
View Article and Find Full Text PDFMachine-Learning-Aided Engineering Hemoglobin as Carbene Transferase for Catalyzing Enantioselective Olefin Cyclopropanation.
JACS Au
December 2024
Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun 130023, P. R. China.
In this study, we developed a machine-learning-aided protein design strategy for engineering hemoglobin (VHb) as carbene transferase. A Natural Language Processing (NLP) model was used for the first time to construct an algorithm (EESP, enzyme enantioselectivity score predictor) and predict the enantioselectivity of VHb. We identified critical amino acid residue sites by molecular docking and established a simplified mutation library by site-saturated mutagenesis.
View Article and Find Full Text PDFNeutral 4π-electron tetrasilacyclobutadiene contains unusual features of a Möbius-type aromatic ring.
Commun Chem
December 2024
Anorganische Chemie, Universität Göttingen, Göttingen, Germany.
The search for stable compounds containing an antiaromatic cyclic 4π system is a challenge for inventive chemists that can look back on a long history. Here we report the isolation and characterization of the novel 4π-electron tetrasilacyclobutadiene, an analogue of a 4π neutral cyclobutadiene that exhibits surprising features of a Möbius-type aromatic ring. Reduction of RSiCl (R = (Pr)PCH) with KC in the presence of cycloalkyl amino-carbene (cAAC) led to the formation of corresponding silylene 1.
View Article and Find Full Text PDFSynthesis of Carboxylic Acids Containing α-All-Carbon Quaternary Centers from Diazo Compounds and Trialkylboranes.
J Org Chem
December 2024
Beijing National Laboratory of Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China.
The construction of C-C bonds to form all-carbon quaternary centers remains a significant challenge in synthetic chemistry. Herein, we report a tandem process involving a 1,2-migration of a tetra-coordinated boron intermediate followed by a Claisen rearrangement of the boron enolate, achieved through a reaction between allyl diazoacetates and trialkylboranes. The transformation forms two C-C bonds at the carbenic position of diazo substrate in a single-step operation under neutral conditions.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!