Article
Chemistry, Multidisciplinary
Masamichi Yasui, Kengo Hanaya, Takeshi Sugai, Shuhei Higashibayashi
Summary: The metal-free thermal organocatalytic pinacol coupling of arylaldehydes has been developed, leading to the synthesis of various 1,2-diols. The reaction showed good tolerance towards different functional groups.
Article
Multidisciplinary Sciences
Hui Zhou, Yu Zhou, Han Yong Bae, Markus Leutzsch, Yihang Li, Chandra Kanta De, Gui-Juan Cheng, Benjamin List
Summary: Enzymatic stereoselectivity is often better than most chemical catalysts in the conversion of small substrates. A recent study has reported the development of broadly applicable confined organocatalysts for the highly enantioselective cyanosilylation reaction. The selectivity (98:2 enantiomeric ratio) of the catalyst towards the pharmaceutically relevant product exceeds any other catalyst class, including engineered biocatalysts.
Editorial Material
Biochemistry & Molecular Biology
Christopher R. Horne, James M. Murphy
Summary: In this study, the structure of the pseudokinase domain of IRAK3 was reported, revealing a head-to-head dimer formation and a potential mode of regulation for attenuating IRAK4 activity.
Article
Chemistry, Multidisciplinary
Mithilesh Kumar Nayak, Simon Suhr, Nicolas Chrysochos, Hemant Rawat, Carola Schulzke, Vadapalli Chandrasekhar, Biprajit Sarkar, Anukul Jana
Summary: In this study, tethered cyclic(alkyl)(amino)carbene (CAAC) dimers were reported, in which two CAAC motifs are connected by an ethylene-, trans-1,2-cyclohexylene- and propylene-spacer through their N-centres. The 1-electron oxidized radical cations are isolable, and the bridging unit significantly affects the chemical reactivity in and with the 2-electron oxidized products.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Hui Zhou, Roberta Properzi, Markus Leutzsch, Paola Belanzoni, Giovanni Bistoni, Nobuya Tsuji, Jung Tae Han, Chendan Zhu, Benjamin List
Summary: Chiral organosilanes are not naturally occurring and are therefore rare. However, a new synthetic approach using racemic silanes as starting materials has been developed, which expands the range of accessible Si-stereogenic compounds. This approach involves the use of strong and confined imidodiphosphorimidate (IDPi) catalysts to enable the dynamic kinetic asymmetric transformation (DYKAT) of racemic allyl silanes, leading to the formation of Si-stereogenic silyl ethers. The products can be easily converted into enantiopure monohydrosilanes. A proposed mechanism involves the epimerization of a catalyst-bound intermediate.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Jia-Hao Zeng, Ding-Chang Li, Sheng Zhang, Zhuang-Ping Zhan
Summary: This study presents a chemodivergent protocol for the synthesis of branched and linear allylic sulfones bearing a conjugated (Z,E)-1,3-diene scaffold by Pd-catalyzed coupling of allenes with sulfinic acids. The method features mild conditions, an unprecedented substrate scope, and functional group compatibility.
Article
Chemistry, Multidisciplinary
Arun Yadav, Sabhya Sandha, Chandra Bhushan Tripathi
Summary: An organocatalytic photoinduced 1,2-carbofunctionalization strategy has been developed that enables regioselective and efficient 1,2-carboisothiocyanation of conjugated dienes without the need for exogenous photocatalysts or additives. The reaction is proposed to proceed through EDA complexation between the diene and TMSNCS.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Ye-Hui Chen, Meng Duan, Si-Li Lin, Yu-Wei Liu, Jun Kee Cheng, Shao-Hua Xiang, Peiyuan Yu, Kendall N. Houk, Bin Tan
Summary: This article introduces an effective strategy for umpolung functionalization of imines through aromatization. The attachment of strongly electron-withdrawing groups to imines enhances their reactivity, enabling direct amination of (hetero)arenes. Additionally, the use of chiral catalysts allows for the synthesis of (hetero)aryl C-N atropisomers or enantioenriched aliphatic amines.
Article
Chemistry, Applied
Killian Onida, Alice J. Haddleton, Sebastien Norsic, Christophe Boisson, Franck D'Agosto, Nicolas Duguet
Summary: The study investigated the organocatalytic synthesis of substituted vinylene carbonates using diphenyl carbonate as a carbonyl source. Imidazolium salts were found to be the most effective catalysts for this transformation. The reaction yielded a variety of substituted vinylene carbonates with isolated yields ranging from 20-99%. Additionally, thermomorphic polyethylene-supported organocatalysts were utilized for recoverable and recyclable species, allowing for multiple runs and preparative scale synthesis.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Review
Chemistry, Physical
Mayavan Viji, Srinu Lanka, Jaeuk Sim, Chanhyun Jung, Heesoon Lee, Manjunatha Vishwanath, Jae-Kyung Jung
Summary: Organocatalysts play a crucial role in chemical reactions, allowing for the production of highly enantio- and diastereomeric pure products. Their applications have gained significant attention as they can substitute transition metal catalysts and other toxic reagents, while being cost-effective and environmentally friendly.
Article
Chemistry, Multidisciplinary
Fen Su, Fengfei Lu, Kun Tang, Xiaokang Lv, Zhongfu Luo, Fengrui Che, Hongyan Long, Xingxing Wu, Yonggui Robin Chi
Summary: This study discloses the first organocatalytic direct functionalization/acylation of inert C(sp3)-H bonds of completely unfunctionalized alkanes. The approach involves N-heterocyclic carbene catalyst-mediated carbonyl radical intermediate generation and coupling with simple alkanes through the corresponding alkyl radical intermediates generated via a hydrogen atom transfer process. This method provides a new avenue for functionalization of challenging C-H bonds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Vasco Corti, Casper Larsen Barlose, Niklas Lawaetz ostergaard, Anne Kristensen, Nicolaj Inunnguaq Jessen, Karl Anker Jorgensen
Summary: Chiral eight-membered carbocycles are important in a variety of fields, but their synthesis has been a challenge. The catalytic enantioselective [4 + 4] cycloaddition is an efficient method to obtain these molecules, and we report the first organocatalytic asymmetric [4 + 4] cycloaddition of 9H-fluorene-1-carbaldehydes with electron-deficient dienes. The reaction concept is based on aminocatalytic formation of a polarized butadiene component and allows for the construction of cyclooctadiene derivatives with various functionalities.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Weijin Wang, Hongye Wang, Rongheng Dai, Yachong Wang, Zhaoting Li, Xiaoxue Yang, Bin Lu, Ning Jiao, Song Song
Summary: A practical catalytic protocol for the deoxyhalogenation of alcohols with inorganic halides is reported. The method avoids the need for stoichiometric activators and organic halogenating reagents, and allows for the formation of organic bromides and iodides in good yield. Furthermore, the one-pot sequential process enables the formation of C-N, C-O, C-F, C-Cl, and C-S bonds with good yield.
Article
Chemistry, Organic
Stuart C. Davidson, Gabriel dos Passos Gomes, Leah R. Kuhn, Igor Alabugin, Alan R. Kennedy, Nicholas C. O. Tomkinson
Summary: The treatment of sulfide with a 1,3-diketone in the presence of silica sulfuric acid and hydrogen peroxide leads to the corresponding sulfoxide product. The tris-peroxide formed in the reaction can oxidize sulfide and experimental observations suggest a mechanism involving acid-catalyzed ring opening.
Article
Chemistry, Organic
Chandrakanta Parida, Subhas Chandra Pan
Summary: Here, we describe the first synthesis of furan-embedded styrene atropisomers by reacting 1-(aryl-ethynyl)-naphthalen-2-ol with α-hydroxyenone. The reaction involves in situ furan formation from α-hydroxyenone. With a catalytic amount of PTSA, the styrene derivatives are obtained in moderate to good yields with high diastereoselectivities. Various applications including triazole formation and cross-coupling reactions have been demonstrated, and a preliminary catalytic asymmetric version has also been reported.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Manashi Panda, Mukulesh Mondal, Shi Chen, Ahmad A. Ibrahim, Dylan J. Twardy, Nessan J. Kerrigan
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Organic
Ahmad A. Ibrahim, Pei-Hsun Wei, Gero D. Harzmann, Divya Nalla, Mukulesh Mondal, Kraig A. Wheeler, Nessan J. Kerrigan
Summary: This article discusses the full details of optimization studies of the phosphine-catalyzed ketene homodimerization reaction and the development of an asymmetric variant. It also reveals studies towards the development of a phosphine-catalyzed ketene heterodimerization reaction, and includes a discussion of possible reaction mechanisms supported by spectroscopic analysis of intermediates and trapping experiments.
Article
Medicine, General & Internal
Mohd Asyraf Zulkifley, Nur Ayuni Mohamed, Siti Raihanah Abdani, Nor Azwan Mohamed Kamari, Asraf Mohamed Moubark, Ahmad Asrul Ibrahim
Summary: Skeletal bone age assessment using X-ray images is a standard clinical procedure to detect anomalies in bone growth among children, but traditional manual methods are heavily reliant on individual expertise, leading to potential biases in results.
Article
Thermodynamics
Achikkulath Prasanthi, Hussain Shareef, Madathodika Asna, Ahmad Asrul Ibrahim, Rachid Errouissi
Summary: This paper proposes an optimal hybrid energy sources sizing methodology for hybrid electric vehicles, comprising ultracapacitor (UC) and fuel cell (FC) with battery units (BU). By formulating a multi objective problem using dynamic-source models and adaptive energy management strategy, the optimization problem is effectively addressed. The performance evaluation shows significant benefits in downsizing battery rating and reducing system relative cost and weight using the improved butterfly optimization algorithm and the proposed energy management strategy.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Engineering, Electrical & Electronic
M. S. Ali, Mahidur R. Sarker, Ahmad Asrul Ibrahim, Ramizi Mohamed
Summary: Flywheel energy storage systems, also known as flywheel motor generator systems, are essential for power stability in various fields such as micro-grids, transportation, portable power supply, and renewable energy power stations like solar or wind. These systems contribute significantly to stabilizing power production and reducing power consumption. In industries with high power consumption, such as spray dryer factories, efficient FMG systems can serve as alternative power backups to effectively reduce power consumption.
PRZEGLAD ELEKTROTECHNICZNY
(2021)
Article
Chemistry, Analytical
Nur Ayuni Mohamed, Mohd Asyraf Zulkifley, Ahmad Asrul Ibrahim, Mustapha Aouache
Summary: Research on fall event detection has led to the proposal of the SmartConvFall automated fall frame detection system, which aims to minimize fall consequences by detecting the exact fall frame in a video sequence. The system consists of object tracking and instantaneous fall frame detection modules that rely on deep learning representations, with various training configurations evaluated to achieve optimal performance.
Article
Engineering, Electrical & Electronic
Nurul Afiqah Mohd Fazzil, Ahmad Asrul Ibrahim, Hussain Shareef, Mohd Asyraf Zulkifley, Muhammad Akmal Remli
Summary: This study aims to determine the status of individual appliances from aggregated measurements using non-intrusive load monitoring (NILM) based on a feed-forward neural network. A new approach using a threshold to identify the status of appliances based on their power consumption readings is introduced. The results show that the NILM using a feed-forward neural network outperformed the traditional logistic regression by 5.78% in terms of accuracy.
PRZEGLAD ELEKTROTECHNICZNY
(2022)
Review
Engineering, Electrical & Electronic
Asiful Habib, Muhammad Ammirrul Atiqi Mohd Zainuri, Hang Seng Che, Ahmad Asrul Ibrahim, Nasrudin Abd Rahim, Zuhair Muhammed Alaas, Mohamed Mostafa Ramadan Ahmed
Summary: Coreless axial-flux permanent-magnet (AFPM) machines have gained attention due to their coreless structure, which offers higher efficiency and lower cogging torque. However, limitations such as high leakage flux and weak mechanical structure hinder their wide application. This systematic review identifies key research areas in coreless AFPM, including the development of efficient designs for multiphase and multi-stage topologies, as well as lightweight rotor and stator structures.
IET ELECTRIC POWER APPLICATIONS
(2022)
Review
Medicine, General & Internal
Mohammad J. M. Zedan, Mohd Asyraf Zulkifley, Ahmad Asrul Ibrahim, Asraf Mohamed Moubark, Nor Azwan Mohamed Kamari, Siti Raihanah Abdani
Summary: Glaucoma is a chronic eye disease that can cause permanent vision loss if not diagnosed and treated early. Algorithms based on deep learning techniques have been designed to screen and diagnose glaucoma using retinal fundus images, improving accuracy and efficiency in glaucoma diagnosis.
Article
Computer Science, Theory & Methods
Ahamed Ibrahim Sithy Juhaniya, Ahmad Asrul Ibrahim, Muhammad Ammirrul Atiqi Mohd Zainuri, Mohd Asyraf Zulkifley
Summary: Induction motors are commonly used in electricity generation, but their performance is influenced by rotor design and machine geometry. By studying the variation of rotor slot geometry parameters, the efficiency of induction motors can be improved.
INTERNATIONAL JOURNAL OF ADVANCED COMPUTER SCIENCE AND APPLICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Ahamed Ibrahim Sithy Juhaniya, Ahmad Asrul Ibrahim, Muhammad Ammirrul Atiqi Mohd Zainuri, Mohd Asyraf Zulkifley, Muhammad Akmal Remli
Summary: This study presents a hybrid optimization technique for the design of induction motors in electric vehicles. The proposed technique, called OBJSO, combines opposition-based learning and jellyfish search optimization to improve convergence rate and achieve better optimization results. By maximizing the main performance indicators of electric vehicles, including efficiency, breakdown torque, and power factor, this technique can help engineers design high-performance motors.
Proceedings Paper
Computer Science, Software Engineering
Syukri Zamri, Mohd Hairi Mohd Zaman, Asraf Mohamed Moubark, Ahmad Asrul Ibrahim, Mohd Hafiz Baharuddin
Summary: Linear voltage regulator instability due to load current change can be compensated by connecting an output capacitor with specific equivalent series resistance. Precise stability condition can be obtained by measuring the phase margin based on frequency response. Machine learning methods were proposed to estimate the phase margin, with Gaussian process regression producing the best results.
2022 IEEE 18TH INTERNATIONAL COLLOQUIUM ON SIGNAL PROCESSING & APPLICATIONS (CSPA 2022)
(2022)
Proceedings Paper
Computer Science, Theory & Methods
Mohd Farhan Mohd Ali, Ahmad Asrul Ibrahim, Mohd Hairi Mohd Zaman
Summary: The study aims to determine the optimal size of a photovoltaic (PV) system to reduce power consumption of a smart aquaponic system by utilizing IoT technology for continuous monitoring and autonomous operation, and leveraging solar resources. The research involves the development of the smart aquaponic system, data collection, and determining the optimal size of the PV system.
19TH IEEE STUDENT CONFERENCE ON RESEARCH AND DEVELOPMENT (SCORED 2021)
(2021)
Article
Engineering, Electrical & Electronic
Saad Saleem Khan, Hussain Shareef, Ahmad Asrul Ibrahim
Summary: The paper presents a new dynamic semi-empirical model for water management in proton exchange membrane fuel cell systems, which calculates internal oxygen and hydrogen partial pressures without special internal sensors, and models membrane water content and internal resistances based on load current and temperature conditions. The parameters of the model are optimized using a quantum lightning search algorithm, and its performance is validated with experimental data, demonstrating its capability for fault detection and diagnosis in PEMFC systems.
JOURNAL OF MODERN POWER SYSTEMS AND CLEAN ENERGY
(2021)
Article
Chemistry, Organic
Ahmad A. Ibrahim, Gero D. Harzmann, Divya Nalla, Beth Elledge, Max Van Raaphorst, Nessan J. Kerrigan
Summary: The study focused on the reaction of heteroatom nucleophiles with ketene dimers, synthesizing Weinreb amide derivatives with excellent retention of chirality but poor diastereoselectivity. The research also applied to asymmetric synthesis and sequential one-pot reactions successfully.
