Review
Chemistry, Applied
Hongxiang Li, Honglei Liu, Hongchao Guo
Summary: Quaternary phosphonium salts are extensively used as Lewis acid organocatalysts in organic synthesis, particularly for Mannich, Strecker, and Friedel-Crafts reactions, allowing the construction of structurally diverse and synthetically useful architectures.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Andreas Eitzinger, Jan Otevrel, Victoria Haider, Antonio Macchia, Antonio Massa, Kirill Faust, Bernhard Spingler, Albrecht Berkessel, Mario Waser
Summary: In this study, chiral 3,3-disubstituted isoindolinones were synthesized using ammonium salt catalysis, yielding a variety of differently substituted CF3S- and RS-derivatives with high enantioselectivities. Additionally, a racemic synthesis of F-containing products was achieved for the first time, producing a stable alpha-F-alpha-amino acid derivative.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Soumen Barik, Sayan Shee, Soumik Das, Rajesh G. Gonnade, Garima Jindal, Subrata Mukherjee, Akkattu T. Biju
Summary: This study describes the atroposelective synthesis of N-aryl succinimides with axially chiral C-N bonds catalyzed by N-heterocyclic carbenes, achieving good yields and ee values. Preliminary investigations were also conducted on the rotation barrier for the C-N bond, temperature dependence, and detailed DFT studies on the mechanism.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Zhibin Guo, Daehyun Oh, Min Sagong, Jewon Yang, Geumwoo Lee, Hyeung-geun Park
Summary: An efficient method for synthesizing chiral malonates was established using enantioselective phase transfer catalysis. The a-alkylation reaction of 2,2-diphenylethyl tert-butyl a-methylmalonates with (S,S)-3,4,5-trifluorophenyl-NAS bromide as a phase-transfer catalyst successfully yielded corresponding a-methyl-a-alkylmalonates. These compounds are versatile chiral building blocks with a quaternary carbon center, obtained in high chemical yields (up to 99%) and excellent enantioselectivities (up to 98% ee). Selective hydrolysis of a,a-dialkylmalonates to the corresponding chiral malonic monoacids was achieved using basic (KOH/MeOH) and acidic conditions (TFA/CH2Cl2), demonstrating the practicality of the method.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Sei Murayama, Zhurong Li, Huatai Liang, Yan Liu, Hiroshi Naka, Keiji Maruoka
Summary: Site-specifically deuterated organocatalysts exhibit enhanced reactivity compared to non-deuterated analogs in the asymmetric catalytic alkylation of amino acid derivatives. The stability of phase-transfer catalysts can be improved by site-specific deuteration, with a significant secondary kinetic isotope effect observed for tetradeuterated catalysts. These findings suggest that catalyst deuteration is a promising strategy to enhance the stability and performance of organocatalysts.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Ken Okuno, Takumi Nakamura, Seiji Shirakawa
Summary: This study reports the synthesis and asymmetric catalysis of chiral bifunctional selenides and selenonium salts, which promote asymmetric halocyclizations and phase-transfer conjugate additions.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Feng-Tao Sheng, Shuang Yang, Shu-Fang Wu, Yu-Chen Zhang, Feng Shi
Summary: A new strategy for the enantioselective synthesis of axially chiral 3,3'-bisindoles was developed by directly coupling two indole rings using the C3-umpolung reactivity of 2-indolylmethanols. The synthesized compounds can be further modified to create axially chiral 3,3'-bisindole-based organocatalysts for asymmetric catalysis.
CHINESE JOURNAL OF CHEMISTRY
(2022)
Review
Chemistry, Organic
Helene Pellissier
Summary: Organocatalytic dynamic kinetic resolution (DKR) has emerged as a promising field in the past two decades, allowing efficient separation of chiral compounds. This review aims to provide an update on organocatalytic DKRs since 2016.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Ming-Sheng Xie, Ning Li, Yin Tian, Xiao-Xia Wu, Yun Deng, Gui-Rong Qu, Hai-Ming Guo
Summary: A study reported the use of bifunctional chiral PPY N-oxides as catalysts for dynamic kinetic resolution of racemic carboxylic esters, achieving high yields and enantioselectivity for the synthesis of chiral alpha-aryl alpha-alkyl carboxylic esters. Mechanistic studies revealed the crucial role of oxygen atoms in PPY N-oxides during the reaction process.
Article
Chemistry, Physical
Ilya D. Gridnev
Summary: Recent studies on the mechanism of asymmetric hydrogenation catalyzed by transition metal complexes suggest that hydrogen activation and enantioselectivity generation are independent processes. This conclusion opens up new possibilities for rational catalyst design.
Article
Chemistry, Organic
Istvan Orban, Bertalan Varga, Peter Bagi, Tamas Holczbauer, Zsolt Rapi
Summary: Enantioenriched, highly functionalized cyclopropane derivatives with complete diastereoselectivity and up to 87% enantioselectivity were prepared using monosaccharide-based chiral crown ethers as phase transfer catalysts. Among the catalysts tested, the monoaza-15-crown-5 lariat ether with a methyl beta-D-glucopyranoside unit and a 2-(3,4-dimethoxyphenyl)ethyl group on the nitrogen exhibited the highest asymmetric induction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Nobuya Tsuji, Pavel Sidorov, Chendan Zhu, Yuuya Nagata, Timur Gimadiev, Alexandre Varnek, Benjamin List
Summary: Catalyst optimization processes often rely on qualitative assumptions of chemists based on screening data, while machine learning models using molecular properties or calculated 3D structures are time-consuming and costly. This study proposes a machine learning model based on fragment descriptors, which are fine-tuned for asymmetric catalysis and result in robust and efficient virtual screening. Through theoretical design and experimental validation, new catalysts with higher selectivities in a challenging synthesis were developed using only moderately selective training data.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Physical
Wang Yao, Emmanuel A. Bazan-Bergamin, Ming-Yu Ngai
Summary: Visible-light photocatalysis is a versatile tool in organic synthesis, but achieving precise stereocontrol has been a challenge. Innovative strategies, including the use of chiral organocatalysts, have emerged to address this issue and expand the applications of photocatalytic reactions. These strategies provide new possibilities for the development of asymmetric photocatalytic reactions.
Article
Chemistry, Applied
Claire Segovia, Jeremy Godemert, Jean-Francois Briere, Vincent Levacher, Sylvain Oudeyer
Summary: An organocatalyzed one-pot sequential deracemization of aromatic ketones with a stereogenic center at the alpha-position was achieved through an acid-base strategy, in which enantioselective protonation reaction played a key role. This protocol provides enantioenriched ketones with up to 89% ee without isolating sensitive intermediates like silyl enolates. Water was found to be crucial in this process. This one-pot sequence serves as a valuable extension to previously reported chemically driven red-ox protocols, expanding the range of molecules eligible for deracemization.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Yuanyuan Li, Longhui Duan, Biqiong Hong, Zhenhua Gu
Summary: This study developed a copper-catalyzed enantioselective ring-opening reaction, which can selectively advance the synthesis of different functionalized compounds starting from 2,2'-dibromo-6,6'-diiodo-1,1'-biphenyl. Through a series of functionalization reactions, a new and convenient approach for synthesizing functionalized axially chiral biphenyls was introduced.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Physical
Mona Jalali, Farshad Shiri, Alex C. Bissember, Brian F. Yates, Alireza Ariafard
Summary: Density functional theory (DFT) was used to investigate the mechanism of the efficient hydroalkylation of styrene with acetylacetone in the presence of a bismuth catalyst. The results show that the mechanism is fundamentally different from the analogous gold-catalyzed reaction and is characterized by bismuth coordinating to the oxygens of acetylacetone to form a chelated complex. The activation energy for the reaction with bismuth via the enol isomer of acetylacetone is much lower compared to the ketone isomer.
Article
Multidisciplinary Sciences
Xuefeng Tan, Qingli Wang, Jianwei Sun
Summary: The authors have successfully achieved catalytic asymmetric bromocyclization processes induced by weak ion-pairing interaction under electrochemical conditions. This overcomes the challenges related to solvent polarity and electrolyte interference, allowing for electricity-driven asymmetric catalysis.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Kristy W. K. Lam, Joe H. C. Chau, Eric Y. Yu, Feiyi Sun, Jacky W. Y. Lam, Dan Ding, Ryan T. K. Kwok, Jianwei Sun, Xuewen He, Ben Zhong Tang
Summary: In this study, a phosphate group was introduced as a cancer-specific biomarker of alkaline phosphatase (ALP) on a photosensitizer (PS) with aggregation-induced emission (AIE) for cancer cell imaging and therapy. The phosphate group on the PS is selectively hydrolyzed by ALP in high ALP expressing cancer cells, leading to aggregation and fluorescent response. Furthermore, fluorescence-guided photodynamic therapy (PDT) was achieved by using the aggregates of PS with strong reactive oxygen species (ROS) generation efficiency under white light irradiation.
Article
Chemistry, Multidisciplinary
Jackson S. Henneveld, Farshad Shiri, Alireza Ariafard, Nigel T. Lucas, Alex C. Bissember, Bill C. Hawkins
Summary: The investigation and formalization of the distinctive dipole-transmissive dipolar cycloaddition (DTDC) methodology is reported. A DTDC procedure was developed by taking advantage of the structural complementarity of azide and diazoalkane 1,3-dipoles. This method allows for the rapid construction of functionalized polycyclic N-heterocycles through intramolecular azide-alkene 1,3-dipolar cycloadditions followed by N-derivatization and subsequent 1,3-dipolar cycloadditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Angus Olding, Curtis C. Ho, Nigel T. Lucas, Alex C. Bissember
Summary: In this study, a range of unprecedented, kinetically stable alkyl-, alkenyl-, allenyl-, and alkynylpalladium(II) boronates were prepared from various Csp3, Csp2, and Csp electrophiles via a simple, general method. The structures of these complexes were secured by X-ray crystallography, and the chemical competence of a number of these intermediates in transmetalation was demonstrated.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Shuxuan Liu, Ka Lok Chan, Zhenyang Lin, Jianwei Sun
Summary: This article reports the use of extended quinone methides with carbonyl and methide units distributed across two different rings as intermediates for asymmetric synthesis. By using suitable chiral phosphoric acids, the first asymmetric process involving such intermediates was achieved. These processes provide a rapid and highly enantioselective access to previously less accessible remotely chiral naphthols and naphthylamines. Control experiments and DFT calculations reveal important insights into the reaction mechanism, which likely involves the role of two phosphoric acid molecules in the enantiodetermining transition states. This work serves as a proof of concept for the exploitation of new types of extended quinone methides as versatile intermediates for asymmetric synthesis, offering a new platform for the efficient construction of remote benzylic stereogenic centers of aromatic compounds.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Polymer Science
Yunfei Zuo, Ryan T. K. Kwok, Jianwei Sun, Jacky W. Y. Lam, Ben Zhong Tang
Summary: Recent advancements in aggregation-induced emission (AIE) macromolecular materials have received attention as potential antibacterial solutions, providing new approaches for treating multidrug-resistant infections and biofilms, as well as real-time monitoring and specific targeting of bacteria. This review discusses the three main categories of AIE macromolecular materials with antibacterial properties and their mechanisms and applications in antibacterial treatment, wound care, and protective equipment. It also highlights the potential for future developments and application directions of AIE-based antimicrobial materials.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Biochemistry & Molecular Biology
Samuel D. Zarfos, Bianca J. Deans, Curtis C. Ho, Gregory J. Jordan, Jason A. Smith, Alex C. Bissember
Summary: This study focused on the isolation of natural products from eight Tasmanian Proteaceae species and three Australian Proteaceae species. Two previously unreported natural products and four rare arbutin esters were identified, supporting the idea that these unique arbutin esters can serve as markers for the chemical evolution of plant species within the Proteaceae family.
CHEMISTRY & BIODIVERSITY
(2023)
Article
Chemistry, Multidisciplinary
Liang Zhang, Shu-Cheng Wan, Jianyu Zhang, Meng-Jie Zhang, Qi-Chao Yang, Boxin Zhang, Wu-Yin Wang, Jianwei Sun, Ryan T. K. Kwok, Jacky W. Y. Lam, Hexiang Deng, Zhi-Jun Sun, Ben Zhong Tang
Summary: Covalent organic frameworks (COFs) have shown potential as porous materials for cancer phototherapy due to their unique characteristics. However, the aggregation-caused quenching effect and apoptosis resistance limit their effectiveness. This study demonstrated that linking AIEgens into COF networks was an effective strategy for inducing pyroptosis and enhancing antitumor immunity. The synergized system of AIE COF and αPD-1 effectively eradicated tumors and inhibited recurrence and metastasis in a tumor model.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Qicheng Yu, Jianyu Zhang, Jacky W. Y. Lam, Dong Yang, Jianwei Sun, Ben Zhong Tang
Summary: This research focuses on the development of room-temperature phosphorescent metal-organic frameworks (MOFs) with free heavy metal atoms, high quantum yields, and long lifetime. It is demonstrated that by ligand functionalization, heavy-atom-free CAU-10 MOFs with color-, lifetime-, and intensity-tunable intrinsic room temperature phosphorescence (RTP) can be achieved. The strong metal-organic coordination bond and firm anchoring of ligands make the MOFs show superior RTP performance and stability compared to pure organic ligands' crystals.
ACS MATERIALS LETTERS
(2023)
Article
Polymer Science
Yeasmin Nahar, Melissa K. Stanfield, Alex C. Bissember, Stuart C. Thickett
Summary: We successfully prepared poly(N-isopropylacrylamide)-block-poly(epsilon-caprolactone) (pNIPAM-b-pCL) block copolymers through simultaneous RAFT polymerization and anionic ring-opening polymerization (ROP) of NIPAM and CL respectively without traditional solvents. The use of a polymerizable eutectic led to higher reaction rates compared to reactions in typical organic solvents, demonstrating the advantage of this synthetic approach.
Article
Chemistry, Multidisciplinary
Angus Olding, Curtis C. Ho, Debabrata Maiti, Alex C. Bissember
Summary: This article explores a series of case studies that examine key strategies enabling the structural authentication of important species in palladium- and nickel-catalysed C-C, C-N, and C-O cross-coupling reactions. It focuses on studies confirming the structures of challenging intermediates using X-ray crystallography, while providing mechanistic insights from these reports.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Jie Wang, Run Yu, Cuicui Nian, Maoyan Liao, Zhengyu Han, Jianwei Sun, Hai Huang
Summary: Direct arylation of the benzylic C-(sp(3))-H bond is a straightforward strategy for the synthesis of multi-aryl methanes. In this paper, the first metal-free arylation of the C-(sp(3))-H bond in 3-methylindoles was developed, leading to the synthesis of diaryl- and triarylmethanes with two indole rings. The key intermediate in this reaction is the 3-indole imine methide. Water plays an important role in facilitating the crucial 1,3-proton transfer step and enhancing the reaction efficiency.
Article
Chemistry, Multidisciplinary
Jixing Li, Ming Fang, Maoyan Liao, Hongling Xie, Xiu-Qin Dong, Zhengyu Han, Jianwei Sun, Hai Huang
Summary: A tandem strategy has been developed for the synthesis of medium-sized heterocycles from oxetanes through the allylic amination/ring-opening of oxetanes.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Huilin Zhan, Bin Chen, Biao Zhu, Xiang Li, Zhengyu Han, Jianwei Sun, Hai Huang
Summary: Based on a halopalladation strategy, we have developed a haloesterification reaction of propargylic amides to synthesize a diverse range of 5-(halomethylene)oxazolidine-2,4-diones. The reaction shows good yield and compatibility with various functional groups. Additionally, we have achieved the cyclizative dimerization of propargylic amides to produce bisoxazolidine-2,4-dione derivatives.
CHEMICAL COMMUNICATIONS
(2023)
