Review
Biochemistry & Molecular Biology
Vincent Ritleng, Christophe Michon
Summary: This review focuses on the application of ruthenium complexes with bidentate donor-functionalized N-heterocyclic carbene ligands in catalyzing hydrogen transfer reactions, and discusses the effects of different donor atoms and carbene ligands on the transfer hydrogenation reactions. This research is important for improving the efficiency and selectivity of catalytic hydrogen transfer reactions.
Review
Chemistry, Multidisciplinary
Kun-Quan Chen, He Sheng, Qiang Liu, Pan-Lin Shao, Xiang-Yu Chen
Summary: In recent years, NHC-catalyzed radical reactions have been gaining attention for their potential to create new activation modes previously inaccessible. Further research and understanding of this emerging area is warranted to explore its synthetic techniques and advantages.
SCIENCE CHINA-CHEMISTRY
(2021)
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
Yunquan Man, Xiaojun Zeng, Bo Xu
Summary: We have developed an efficient N-heterocyclic carbene (NHC)-catalyzed thioesterification of aldehydes using N-thiosuccinimides as the thiolation reagent. This method allows easy access to highly functionalized thioesters and demonstrates good chemical yields and functional group tolerance.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
En Li, Kai Tang, Zhuhui Ren, Xiaoyun Liao, Qianchen Liu, Yong Huang, Jiean Chen
Summary: The successful enantioselective beta-alkylation of homoenolates using C-sp3 electrophiles through an S(N)2 strategy is reported. The method shows a broad scope and delivers good yields and excellent enantioselectivities (up to 99% ee). It enables the installation of drug-like structural motifs and presents a concise synthetic route to chiral pyrroloindoline-type skeletons. Preliminary mechanistic studies support a direct S(N)2 mechanism.
Article
Chemistry, Multidisciplinary
Ludwig Zapf, Sven Peters, Ruediger Bertermann, Udo Radius, Maik Finze
Summary: This study demonstrates that the charge, coordination site number, volume, σ-donor, and π-acceptor properties of NHCs can be effectively tuned by the number of tricyanoborane substituents.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Min Zhang, Xinghua Wang, Tingting Yang, Yan Qiao, Donghui Wei
Summary: Identifying the special role of N-heterocyclic carbene (NHC) in organocatalysis remains a major challenge. The study proposed a theoretical model for NHC-catalyzed decarboxylation reactions and found that C-H⋯O hydrogen bond interactions significantly contribute to controlling stereoselectivity in these reactions.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Chun -Lin Zhang, Hai-Ying Wang, Ying Huang, Xin-Han Wang, Song Ye
Summary: An N-heterocyclic carbene-catalyzed three-component reaction has been developed for the synthesis of multisubstituted benzenes. The reaction demonstrates mild conditions, high efficiency, and chemoselectivity, leading to the formation of pentasubstituted benzenes in good to high yields.
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
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.
Article
Chemistry, Multidisciplinary
Guanjie Wang, Juhui Huang, Linxue Zhang, Jinna Han, Xiaoxiang Zhang, Jie Huang, Zhenqian Fu, Wei Huang
Summary: Axially chiral molecules are widely used in various fields of chemistry, and the synthesis of axially chiral molecules catalyzed by NHCs remains underdeveloped. In this study, we successfully achieved the atroposelective synthesis of axially chiral heteroaryl-aryls using chiral NHCs as catalysts for highly enantioselective Coates-Claisen rearrangements via catalytically generated alpha, beta-unsaturated acyl azoliums. This approach enables the concise synthesis of tetra-ortho-substituted 2-pyrones with good yield and chirality control.
SCIENCE CHINA-CHEMISTRY
(2022)
Article
Chemistry, Organic
Yunpeng Chu, Meng Wu, Fang Hu, Panpan Zhou, Zhengqiang Cao, Xin-Ping Hui
Summary: The first atroposelective synthesis of pyrrolo[3,4-b]pyridines catalyzed by N-heterocyclic carbene has been achieved, leading to a wide range of chiral atropisomers with high yields and excellent enantioselectivities (96-99% enantiomeric excess). Experimental results and density functional theory calculations demonstrate the high thermal stability of the C-N axial chirality in the product.
Article
Chemistry, Organic
Kosuke Yasui, Miharu Kamitani, Hayato Fujimoto, Mamoru Tobisu
Summary: This study reports on the N-heterocyclic carbene (NHC)-catalyzed Truce-Smiles rearrangement of aniline derivatives, where an unactivated C(aryl)-N bond is cleaved to form a new C(aryl)-C bond. The key to the success of this reaction lies in the utilization of highly nucleophilic NFIC, which enables the formation of a highly nucleophilic ylide intermediate generated from an alpha,beta-unsaturated amide.
Article
Chemistry, Multidisciplinary
Chuntao Wang, Dong Zhu, Rui Wu, Shifa Zhu
Summary: This study reports a Rh2(II)-catalyzed asymmetric enyne cycloisomerization for the synthesis of chiral difluoromethylated cyclopropane derivatives, which can be easily transformed into highly functionalized difluoromethylated cyclopropanes with vicinal all-carbon quaternary stereocenters through ozonolysis. Mechanistic studies and X-ray crystallography of alkyne-dirhodium complexes suggest that cooperative weak hydrogen bondings between the substrates and the dirhodium catalyst may be crucial in this reaction.
Article
Chemistry, Organic
Killari Satyam, Jakkula Ramarao, Surisetti Suresh
Summary: The NHC-catalyzed intramolecular benzoin condensation-oxidation allows for the expedient synthesis of diverse cyclic 1,2-diketones incorporated in dibenzo-fused seven-membered heterocycles in good to excellent yields under ambient conditions. The transformation appears to proceed through the benzoin intermediate followed by aerobic oxidation.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Md D. Hossain, Carlos Fitzgerald Grandes Reyes, Changhe Zhang, Sung-Po R. Chen, Michael J. Monteiro
Summary: In this study, a monomer was rationally designed to form a nonionic polymer with a flat and tunable upper critical solution temperature (UCST) through reversible addition-fragmentation chain transfer. Strong hydrogen-bonding side groups on the polymer led to sharp coil-to-globule transitions. The UCST of the copolymers increased with a greater butyl methacrylate composition and decreased linearly with NaCl concentration due to the salting-in effect.
Article
Chemistry, Multidisciplinary
Jeremy T. Maddigan-Wyatt, Mitchell T. Blyth, Jhi Ametovski, Michelle L. Coote, Joel F. Hooper, David W. Lupton
Summary: A phosphine-catalyzed approach to pyrrolines has been developed, involving two mechanistically unlinked catalytic processes, and successfully synthesizing various pyrrolines. The reaction shows high sensitivity to the selection of catalysts.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Biochemistry & Molecular Biology
Sarah S. Kermaniyan, Moore Chen, Changhe Zhang, Samuel A. Smith, Angus P. R. Johnston, Chris Such, Georgina K. Such
Summary: pH-responsive nanoparticles have attracted attention for their potential in inducing release at low pH. This study investigates the impact of pH-swellable nanoparticles on biological interactions, particularly endosomal escape. The results suggest limitations with the proton-sponge effect and pH-induced swelling mechanism for inducing endosomal escape.
MACROMOLECULAR BIOSCIENCE
(2022)
Article
Chemistry, Organic
Jose A. Forni, Milena L. Czyz, David W. Lupton, Anastasios Polyzos
Summary: A regioselective C(sp(3))-C(sp(2)) cross coupling reaction between inert gamma-C(sp(3))-H bonds in aliphatic amines and cyanoarenes under electrochemical conditions in flow is reported. The reaction utilizes a removable redox active auxiliary to trigger selective 1,7-hydrogen atom transfer for functionalization of a gamma-position aliphatic C-H bond. The cyanoarene radical anion acts both as a selective arylating reagent and a redox active mediator, enabling controlled one-electron reduction of the redox active auxiliary. This strategy provides a new approach for gamma-C(sp(3))-H bond functionalization to generate sterically crowded carbon centers under mild reaction conditions and without additional catalysts or radical initiators.
TETRAHEDRON LETTERS
(2022)
Article
Chemistry, Organic
Jeremy T. Maddigan-Wyatt, Jing Cao, Jhi Ametovski, Joel F. Hooper, David W. Lupton
Summary: Here, an enantioselective catalytic annulation of electron-poor allenes with aminocrotonates is reported. The reaction proceeds via umpolung gamma-amination and beta-umpolung intramolecular conjugate addition. The reaction provides ready access to chiral compounds with high yields and high enantiomeric ratios, and an assisted tandem-catalytic variant is also proposed.
Article
Chemistry, Multidisciplinary
Simon Cromwell, Randy Sutio, Changhe Zhang, Georgina K. Such, David W. Lupton
Summary: In this study, a reaction cascade involving the addition of C1-pyridinium enolate to thiocarbonyl compounds was reported, leading to the synthesis of a range of dihydrothiophenes and dihydrothiopyrans. Mechanistic investigations and experimental evidence supported the involvement of an activated acid intermediate and turnover limiting cyclization in the reaction pathway, with subsequent formation of β-thiolactone regenerating the catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Microbiology
Laura Perlaza-Jimenez, Kher-Shing Tan, Sarah J. Piper, Rachel M. Johnson, Rebecca S. Bamert, Christopher J. Stubenrauch, Alexander Wright, David Lupton, Trevor Lithgow, Matthew J. Belousoff
Summary: Methicillin-resistant Staphylococcus aureus (MRSA) is a major threat to human health, and its treatment often requires the use of last-line antibiotics like linezolid. This study identified linezolid-resistant mutants in MRSA strains and found that mutations in the ribosomal protein uL3 were responsible for the resistance. Cryo-electron microscopic analysis revealed structural rearrangements in the ribosome caused by these mutations.
MICROBIOLOGY SPECTRUM
(2022)
Article
Biochemistry & Molecular Biology
Suk Woo Kang, James Antoney, David W. Lupton, Robert Speight, Colin Scott, Colin J. Jackson
Summary: The stereoselective reduction of alkenes conjugated to electron-withdrawing groups has been extensively studied for the commercial production of fine chemicals. The old yellow enzyme (OYE) family and a subset of flavin/deazaflavin oxidoreductases (FDOR) have been shown to exhibit complementary enantioselectivity. This study explores several enzymes of the FDOR-A subgroup and identifies two enzymes (MSMEG_2027 and MSMEG_2850) that can selectively reduce a wide range of compounds. Protein crystallography and computational docking provide mechanistic insights into the observed stereoselectivity. These findings highlight the potential of FDOR and OYE families in asymmetric ene-reduction.
Article
Chemistry, Medicinal
Biljana Vujcic, Jessica Wyllie, Tania, Jed Burns, Keith F. White, Simon Cromwell, David W. Lupton, Jason L. Dutton, Tatiana P. Soares da Costa, Sevan D. Houston
Summary: The threat of a post-antibiotic era is caused by the rise of antibacterial resistance and depletion of effective antibiotic agents. One solution is to reengineer existing antibiotic drugs by covalently linking two pharmacophores using cage hydrocarbons like cubane, BCO, adamantane, and BCP as linkers. This report demonstrates the successful construction of dimers based on trimethoprim and tedizolid antibiotics using these hydrocarbons. The design strategy presented highlights the potential of this group as a platform for the rapid and modular construction of novel antibiotics.
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS
(2023)
Article
Biochemistry & Molecular Biology
Suk Woo Kang, James Antoney, David W. Lupton, Robert Speight, Colin Scott, Colin J. Jackson
Summary: Asymmetric reduction by ene-reductases has been extensively studied, with the Old Yellow Enzyme (OYE) family being the most researched. However, the limited substrate range and stereocomplementary pairs of current ene-reductases necessitate the development of a complementary class. Flavin/deazaflavin oxidoreductases (FDORs) that use F-420 as a cofactor have gained attention due to their stereocomplementarity with OYEs. In this study, the activity of eight FDOR-B enzymes was investigated, comparing their specific activity, kinetic properties, and stereoselectivity with FDOR-A enzymes and OYE family.
Editorial Material
Multidisciplinary Sciences
Yuji Nakano, David W. Lupton
Review
Chemistry, Multidisciplinary
Yuji Nakano, Jeremy T. Maddigan-Wyatt, David W. Lupton
Summary: Conjugate acceptors are commonly used electrophilic functional groups in organic synthesis. Our research focuses on their ability to undergo polarity inversion through the conjugate addition of Lewis base catalysts. We have achieved cycloisomerizations and annulation reactions using simple conjugate acceptors and those embedded within more complicated substrates. However, significant challenges remain to be addressed before a universal approach to polarity inversion of all conjugate acceptors can be achieved.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Jing Cao, Antonia Seitz, Jose A. Forni, Anastasios Polyzos, David W. Lupton
Summary: This article reports on a reaction design that avoids the facile oxidation of phosphine organocatalyst and combines traditional nucleophilic phosphine organocatalysis with photoredox catalysis to enable Giese coupling with ynoates. The approach exhibits good generality, and its mechanism is supported by cyclic voltametric, Stern-Volmer quenching, and interception studies.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Samuel A. Smith, Bruna Rossi Herling, Changhe Zhang, Maximilian A. Beach, Serena L. Y. Teo, Elizabeth R. Gillies, Angus P. R. Johnston, Georgina K. Such
Summary: A new type of nanoparticles composed of pH-responsive polymer and self-immolative polymer have been developed, which have good drug release properties and biodegradability, and have potential applications in tumor treatment.
