Article
Chemistry, Inorganic & Nuclear
Luong Phong Ho, Matthias Tamm
Summary: In this study, chalcogen-pnictogen dihalide complexes with anionic N-heterocyclic carbene ligands containing a weakly coordinating borate moiety were isolated and characterized.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Shintaro Takahashi, Akihiko Ishii, Norio Nakata
Summary: <P>The sterically demanding iminophosphonamido chlorosilylene [Ph2P(DipN)(2)]SiCl was synthesized and reacted with N- and Fe-nucleophiles, unexpectedly forming corresponding silaimine derivatives. This process involves the ring-opening rearrangement of three-coordinated silylene intermediates that proceeds via intramolecular N-P bond cleavage.</P>
CHEMICAL COMMUNICATIONS
(2021)
Review
Chemistry, Multidisciplinary
Rajendra S. Ghadwal
Summary: This review article aims to highlight recent advances in accessing stable iMICs, quantifying their properties, and exploring their applications in synthesis and catalysis. The synthetic viability and use of vicinal C4,C5-anionic dicarbenes (ADCs) based on a 1,3-imidazole framework are also presented. iMICs and ADCs have the potential to push the limit of classical NHCs by enabling access to conceptually new main-group heterocycles, radicals, molecular catalysts, ligand sets, and more.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yuzhong Wang, Phuong M. Tran, Yaoming Xie, Pingrong Wei, John N. Glushka, Henry F. Schaefer, Gregory H. Robinson
Summary: The study investigated reactions between Lewis bases and an imidazole-based dithione dimer, revealing that both cyclic(alkyl)(amino)carbene and N-heterocyclic carbene can cleave the sulfur-sulfur bonds in the dimer, producing carbene-stabilized dithiolene zwitterions and a spirocyclic silicon-dithiolene compound. The bonding nature of the products was examined using experimental and theoretical methods.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Niklas F. Both, Anke Spannenberg, Haijun Jiao, Kathrin Junge, Matthias Beller
Summary: The use of bis(NHC) manganese(I) complexes 3 as catalysts for the hydrogenation of esters was investigated. Various aromatic and aliphatic esters were successfully hydrogenated at mild temperatures and low catalyst loadings using complexes 3 with KHBEt3 as additive, highlighting the efficiency of the novel catalytic system. Additionally, the versatility of the developed catalytic system was demonstrated by the hydrogenation of other substrate classes like ketones, nitriles, N-heteroarenes, and alkenes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Nadine Weyer, Myron Heinz, Julia I. Schweizer, Clemens Bruhn, Max C. Holthausen, Ulrich Siemeling
Summary: The N-heterocyclic silylene shows a remarkable combination of thermal stability and reactivity towards small molecules, producing different follow-up products in reactions with CO2, N2O, H2O, NH3, and FcPH(2). Unexpectedly, the reaction with H3BNH3 results in B-H activation instead of N-H activation. DFT results suggest dramatically different mechanisms for these H-X insertions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Inorganic & Nuclear
Lingyu Kong, Yajie Chou, Muriel Albalat, Marion Jean, Nicolas Vanthuyne, Stephane Humbel, Paola Nava, Herve Clavier
Summary: The concept of atropisomeric N-heterocyclic carbene (NHC)-metal complexes with C-2-symmetry was extended to palladium-based complexes. Through a comprehensive study of NHC precursors and screening of various NHC ligands, the formation of meso complexes was successfully circumvented. Eight atropisomeric NHC-palladium complexes were prepared and obtained with high enantiopurities through efficient chiral HPLC resolution. These complexes demonstrated good activity in the intramolecular alpha-arylation of amides, leading to the isolation of cyclic products with excellent enantioselectivities (up to 98% ee).
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Louis Monsigny, Anna Kajetanowicz, Karol Grela
Summary: This review discusses a distinct class of ruthenium olefin metathesis catalysts with unsymmetrical N-heterocyclic carbene (uNHC) ligands, highlighting their advantages such as thermodynamic stability, chemical latency, selectivity, and compatibility with green solvents in specialized metathesis transformations. Despite being niche, uNHC complexes have the potential to be implemented in various industrial processes like valorization of Fischer-Tropsch olefin fractions, ethenolysis of renewable products, and modern pharmaceutical production.
Article
Chemistry, Multidisciplinary
Arpan Das, Soumi Chakraborty, Swadhin K. Mandal
Summary: Abnormal N-heterocyclic carbene (aNHC) based Ni(II) pi-allyl complexes (3 and 4) were synthesized from a Ni(0) precursor and characterized. The mechanism for the formation of Ni(II) eta(3)-allyl complexes from a Ni(0) precursor using a free abnormal N-heterocyclic carbene was elucidated. Exposure of complex 3 to O-2 gas under ambient pressure resulted in the activation of molecular oxygen to form a mu-hydroxo bridged Ni(II) dimer.
CHEMISTRY-AN ASIAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Hui Shen, Zhen Xu, Maryam Sabooni Asre Hazer, Qingyuan Wu, Jian Peng, Ruixuan Qin, Sami Malola, Boon K. Teo, Hannu Hakkinen, Nanfeng Zheng
Summary: Deciphering the atomic arrangement of hybrid surface ligands on metal nanoparticles is a key step towards understanding their complex geometrical and electronic structures, which can have potential bio-applications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Yi Ding, Samir Kumar Sarkar, Mohd Nazish, Shahila Muhammed, Daniel Luert, Paul Niklas Ruth, Christina M. Legendre, Regine Herbst-Irmer, Pattiyil Parameswaran, Dietmar Stalke, Zhi Yang, Herbert W. Roesky
Summary: This study reports the stabilization of nitrene reagents for synthesizing nitrogen-incorporated compounds. It was found that the compounds exhibit different structures and reactivity, and were fully characterized using various analytical techniques. Additionally, quantum mechanical calculations revealed the unique characteristics of the nitrogen atoms in these compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Inorganic & Nuclear
Jiawen Lee, Jun Fan, An-Ping Koh, Wan-Jun Joslyn Cheang, Ming-Chung Yang, Ming-Der Su, Cheuk-Wai So
Summary: This study describes the use of an amidinato isopropylmethylamidosilylene catalyst for the efficient hydroboration of carbonyl compounds, resulting in the formation of borate esters. Mechanistic studies reveal the involvement of the Si lone pair electrons and the B vacant p orbital in the reaction process.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Nedra Touj, Jerwin Jay Taping, Nikolay Tumanov, Johan Wouters, Lionel Delaude
Summary: The hydrolysis of imidazolinium chlorides occurs readily in a basic water/dichloromethane biphasic mixture at room temperature. Substrates with alkyl or aryl substituents on their nitrogen atoms led to high yields of gamma-aminoformamides. Bulky alkyl or aryl groups on the formamide moiety resulted in high stereoisomeric purity of the (E)-isomer. The presence of bulky aromatic substituents on the nitrogen atoms slowed down the hydrolysis of certain imidazolinium chlorides. The counteranion was found to have a critical influence on the reactivity of imidazolinium cations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Laura E. English, Aleksandra Pajak, Claire L. McMullin, John P. Lowe, Mary F. Mahon, David J. Liptrot
Summary: Thermolysis of a 1,3-dioxa-2-phospholane supported by the terphenyl ligand Ar-iPr4 (Ar-iPr4=[C6H3-2,6-(C6H3-2,6-iPr(2))]) at 150 degrees C gives [(ArPO2)-P-iPr4](2), a dimeric compound with a 4-membered P-O-P-O ring. The structure of [(ArPO2)-P-iPr4](2) was confirmed by X-ray crystallography and NMR spectroscopy. It was found that the dimeric structure persisted in solution and this was supported by VT NMR spectroscopy and DOSY experiments. The addition of different ligands resulted in increased yield of the product at lower temperature.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
David P. Tilly, William Cullen, Heng Zhong, Romain Jamagne, Inigo Vitorica-Yrezabal, Simon J. Webb
Summary: By investigating the effect of remotely induced changes in ligand folding, a potential pathway towards remote conformational control of organometallic catalysts has been discovered. The study on dynamic folding of Aib peptides revealed that the chiral conformational preference of N-terminal residues can be relayed to the axially chiral Rh(NHC) complex in the helical body.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)