Review
Chemistry, Multidisciplinary
Tingting Li, Zhichao Jin, Yonggui Robin Chi
Summary: This review discusses N-heterocyclic carbene-catalyzed reactions for the formation of aromatic compounds, categorizing them into 4 types based on activation modes. The achievements, challenges, and future research directions in NHC-catalyzed arene construction processes are summarized. The outlook is based on the authors' opinions and knowledge on the trends of NHC organocatalysis development.
SCIENCE CHINA-CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Paul Zaby, Jan Blasius, Anna K. Mueller, Steven P. Nolan, Oldamur Holloczki
Summary: The formation mechanism of metal-N-heterocyclic carbene (NHC) complexes from imidazolium salts in the presence of weak bases was investigated through theoretical methods. Quantum chemical calculations revealed that both sodium acetate and trimethylamine facilitate complex formation. Molecular dynamics simulations showed that the ionic nature of the [AuCl2](-) and imidazolium ions, as well as the sodium acetate base, keep these species associated in the reaction mixture through ion pairing. The neutral amine, however, remains mostly separated from the other reaction partners, making it a significantly less effective base.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Xiaokang Lv, Jun Xu, Cuiyun Sun, Fen Su, Yuanlin Cai, Zhichao Jin, Yonggui Robin Chi
Summary: Ferrocene-derived dicarbaldehydes with pro-chiral planes can be desymmetrized under the catalysis of chiral Nheterocyclic carbene organic catalysts, resulting in enantiomerically enriched planar chiral ferrocene products. The reaction selectively activates and reacts with one aldehyde moiety while leaving the other untouched. The obtained products show potential applications as catalysts in chemical synthesis and for antimicrobial activities in pesticide development.
Article
Chemistry, Multidisciplinary
Ashmita Singh, A. K. Narula
Summary: A facile method for the amidation of aldehydes by a cascade approach has been developed using NHC as the catalyst and NHS as the mediator. The method utilizes TBHP as the oxidant. Various substituted aldehydes reacted smoothly with NHS to form active esters, which were easily converted into amides. The drug moclobemide was successfully synthesized using this methodology to demonstrate its practical utility.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Organic
Zhen Li, Pengju Ji, Jin-Pei Cheng
Summary: A Brønsted basicity scale was established for nine representative N-heterocyclic olefins (NHOs) using an UV-visible spectroscopic method. The unsaturated NHOs were found to have stronger basicities compared to their N-heterocyclic carbene (NHC) analogues, while the basicities of the saturated NHOs were weaker. The nucleophilicity of the NHOs was also stronger than commonly used Lewis bases but weaker than their NHC analogues.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Hang Shen, Michael B. Larsen, Allison G. Roessler, Paul M. Zimmerman, Andrew J. Boydston
Summary: A new flex-activated mechanophore has been discovered, which releases an N-heterocyclic carbene (NHC) under mechanical load. This design demonstrates a promising first step towards flex-activated designs with downstream reactivities, allowing for iterative activation increases in the material through non-destructive compression cycles. The potential modularity of the mechanophore design is highlighted by the demonstration of two different NHC structures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Ludwig Zapf, Udo Radius, Maik Finze
Summary: The paper describes the synthesis of 1,3-bis(tricyanoborane)imidazolate anion and its derivatives, including a novel dianionic N-heterocyclic carbene. These compounds exhibit unique electronic and steric properties, making them promising ligands and building blocks for coordination chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Theo Maulbetsch, Doris Kunz
Summary: The synthesis of a novel NHC-containing porphyrinoid ligand with good fluorescence properties was successfully achieved. Experimental results demonstrated that the heterocyclic moieties in both the ligand and its metal complexes exhibit aromatic character instead of antiaromatic macrocycles.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Biochemistry & Molecular Biology
Ziyang Dong, Chengming Jiang, Changgui Zhao
Summary: In this review, the generation and reactivity of NHC-bound alkynyl acyl azolium intermediates are summarized, covering the progress in the synthesis of achiral and axially chiral cyclic scaffolds via these intermediates. The mechanism related to this intermediate is discussed in detail.
Article
Chemistry, Multidisciplinary
Shenghua Chen, Wen-Hao Li, Wenjun Jiang, Jiarui Yang, Jiexin Zhu, Liqiang Wang, Honghui Ou, Zechao Zhuang, Mingzhao Chen, Xiaohui Sun, Dingsheng Wang, Yadong Li
Summary: This study introduces an efficient CO2RR electrocatalyst with NHC-coordinated Cu SAS embedded in MOF, which exhibits high CH4 FE and TOF, attributed to the σ donation of NHC and the porosity of the catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Junbeom Park, Jaelim Kim, Gu Yoon Jeong, Youngsuk Kim, Eunsung Lee
Summary: This study investigates the electron and proton transfer chemistry of N-heterocyclic carbene nitric oxide radical compounds and prepares a variety of nitrosyl derivatives. The reactions of these derivatives resemble those of transition metal nitrosyl complexes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Matthew P. Sullivan, Monika Cziferszky, Iogann Tolbatov, Dianna Truong, Davide Mercadante, Nazzareno Re, Ronald Gust, David C. Goldstone, Christian G. Hartinger
Summary: Metal complexes exhibit different binding behaviors with proteins, with Ru and Rh complexes targeting surface l-histidine residues, while Os and Ir derivatives predominantly located in electronegative binding pockets after ligand exchange. Computational studies support the binding profiles and suggest the role of protein microenvironment in eliciting selectivity for specific binding sites on the protein.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Yinli Wang, Akiho Yamauchi, Keiji Hashimoto, Tatsuya Fujiwara, Tsubasa Inokuma, Yuta Mitani, Koichi Ute, Satoru Kuwano, Yousuke Yamaoka, Kiyosei Takasu, Ken-ichi Yamada
Summary: We describe a new method of enhancing molecular recognition through substrate-additive complex formation and catalytic acylation using chiral catalyst. The study demonstrates that the additive forms a hydrogen-bonded complex with the substrate, resulting in improved reaction rate and selectivity. The synthetic applications of the resolved compounds highlight the effectiveness of this method.
Article
Biochemical Research Methods
Fady Nahra, Nikolaos Tzouras, Alba Collado, Steven P. Nolan
Summary: N-heterocyclic carbene gold(I) chloride and hydroxide complexes are commonly used as synthetic reagents and efficient catalysts. This study describes a straightforward and practical method for synthesizing mononuclear gold complexes with high yields, as well as the synthesis of a mononuclear gold(I) hydroxide complex and an improved synthesis method for a dinuclear gold(I) hydroxide complex. This methodology offers advantages such as the use of sustainable reaction solvents and commercially available starting materials.
Review
Chemistry, Multidisciplinary
Lei Dai, Song Ye
Summary: N-heterocyclic carbene (NHC)-catalyzed reactions involving two-electron and radical pathways have been well-established, with the former more developed than the latter in terms of reaction types and enantioselectivity. In the past decade, several elegant NHC-catalyzed radical reactions have been developed, including oxidation of aldehydes, reductive coupling reactions, and reactions via radical homoenolates.
CHINESE CHEMICAL LETTERS
(2021)
Article
Biochemical Research Methods
Hayden R. Montgomery, Marco S. Messina, Evan A. Doud, Alexander M. Spokoyny, Heather D. Maynard
Summary: This study presents a facile and benign organometallic approach for synthesizing poly(ethylene glycol) protein conjugates. The method exhibits rapid kinetics and high chemoselectivity, enabling near quantitative conversion at room temperature.
BIOCONJUGATE CHEMISTRY
(2022)
Article
Chemistry, Physical
Narendra P. Arasu, Hector Vazquez
Summary: Interfaces between metals and organic materials are crucial in molecular surface science, photovoltaics, or molecular electronics. This study presents a method for calculating interface parameters based on density functional theory calculations of small metal-molecule complexes. The generated parameter set is used in classical molecular dynamics simulations to gain insights into molecular degrees of freedom inaccessible through ab initio molecular dynamics simulations.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Organic
James W. McDaniel, Julia M. Stauber, Evan A. Doud, Alexander M. Spokoyny, Jennifer M. Murphy
Summary: This study reports a method for labeling unprotected peptides and sugars with a Au(III)-[F-18]fluoroaryl complex, which can generate F-18-labeled S-aryl bioconjugates in an aqueous environment in 15 minutes with high yields and excellent functional group tolerance. The method utilizes a stable organometallic Au(III) complex and highlights the versatility of designer organometallic reagents as efficient agents for rapid radiolabeling.
Article
Chemistry, Physical
Hector Vazquez
Summary: A method is proposed to calculate the tunneling conductance of single molecule junctions using density functional theory. The method reduces computational cost significantly and allows for large-scale conductance calculations, providing a possibility to study the relationship between molecular structure and conductance.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Zelin Miao, Timothy Quainoo, Thomas M. Czyszczon-Burton, Nils Rotthowe, Joseph M. Parr, Zhen-Fei Liu, Michael S. Inkpen
Summary: This study investigates the relationship between chemical structure and conductivity in ordered polymers (OPs) using the scanning tunneling microscope-based break-junction (STM-BJ) method. The results show a negative correlation between junction conductance and electronegativity difference between bridge atoms, and first-principles calculations reveal different nodal structures in transmission eigenchannels. These findings provide insights for the design of OPs.
Article
Chemistry, Multidisciplinary
Liang Li, Shayan Louie, Austin M. Evans, Elena Meirzadeh, Colin Nuckolls, Latha Venkataraman
Summary: Molecular one-dimensional topological insulators (1D TIs) that conduct through low-lying topological edge states have potential for nanoelectronic devices. To observe these effects at longer lengths, we design topological oligo[n]emeraldine wires using short 1D TIs as building blocks. As the wire length increases, the number of topological states increases, enabling increased electronic transmission. The longest oligo[7]emeraldine with doped topological states has over 106 enhancements in transmission compared to its pristine form.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Yujing Wei, Liang Li, Julia E. Greenwald, Latha Venkataraman
Summary: Understanding the relationship between molecular geometry and electronic properties of single-molecule junctions is challenging. In this study, we investigated this relationship by applying a sinusoidal modulation to the molecular junction electrode position. We found that junctions formed with molecules having different molecule-electrode interfaces exhibited statistically distinguishable Fourier-transformed conductances. Our findings suggest that voltage-modulated van der Waals interactions play a significant role in the conductance of single-molecule junctions.
Article
Chemistry, Multidisciplinary
Xiaoyun Pan, Enrique Montes, Wudmir Y. Rojas, Brent Lawson, Hector Vazquez, Maria Kamenetska
Summary: We demonstrate enhanced electronic transport through self-assembled dimer molecular junctions between gold electrodes. The per-molecule conductance of benzimidazole dimers is higher than that of monomers. Our calculations reveal that parallel stacking of two benzimidazoles is energetically favorable due to the large p system. We engineer imidazole derivatives with higher monomer conductance and promote cooperative assembly of more transparent dimer junctions, suggesting the potential of molecular devices based on self-assembled molecular layers.
Article
Chemistry, Inorganic & Nuclear
Christina D. M. Trang, Thomas Saal, Michael S. Inkpen
Summary: We have discovered a new terpyridine ligand with a methyldisulfide group that can be used to prepare metal bis(terpyidine) complexes suitable for functionalizing metal surfaces. These complexes are air-stable in solution for over 7 days, in contrast to their thiol-substituted analogues which decompose. We have also explored the electrochemical properties of these complexes and confirmed their ability to form stable self-assembled monolayers on gold.
DALTON TRANSACTIONS
(2023)
Correction
Chemistry, Multidisciplinary
Nicholas M. Orchanian, Sophia Guizzo, Michael L. Steigerwald, Colin Nuckolls, Latha Venkataraman
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Nicholas M. Orchanian, Sophia Guizzo, Michael L. Steigerwald, Colin Nuckolls, Latha Venkataraman
Summary: The study demonstrates that the reactivity of a kinetically inert transition metal complex can be altered by an external electric field for carbon-carbon coupling reactions. The findings highlight the significance of electric field effects in reaction chemistry and present a novel strategy for modulating organometallic reactivity.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Ilana B. Stone, Rachel L. Starr, Norah Hoffmann, Xiao Wang, Austin M. Evans, Colin Nuckolls, Tristan H. Lambert, Michael L. Steigerwald, Timothy C. Berkelbach, Xavier Roy, Latha Venkataraman
Summary: This study describes the Ullmann coupling of aryl iodides on rough gold surfaces, investigations of the reaction mechanism using experimental and theoretical methods reveal the influence of surface roughness and local electric fields on the reaction, providing important insights for understanding catalysis.
Article
Chemistry, Inorganic & Nuclear
Joseph M. Parr, Clarissa Olivar, Thomas Saal, Ralf Haiges, Michael S. Inkpen
Summary: This study presents a method for synthesizing osmium(IV) tetraaryl complexes using new precursors with lower risk. The relationship between yield and ligand steric bulk is explored by synthesizing different complexes. The results indicate that larger aryl substituents lead to higher yields. Additionally, the study demonstrates the ability to fine-tune the oxidation-reduction properties of the complexes by varying the aryl substituents.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Physical
Hector Vazquez
Summary: This method uses density functional theory to calculate the tunneling conductance of single molecule junctions, simplifying the model and reducing computational costs significantly, while also quantifying the relationship between molecular structure and conductance.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Narendra P. Arasu, Hector Vazquez
Summary: This study describes a method for calculating interface parameters from small metal-molecule complexes based on reference density functional theory calculations, and applies it to develop a parameter set for metal-molecule-metal junctions. Nanosecond classical molecular dynamics simulations using the generated parameter set provide insights into molecular degrees of freedom.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)