Article
Chemistry, Physical
Kai-Lin Yin, Shuang Zhao, Ying Qin, Shu-Han Chen, Bo Li, Dongbing Zhao
Summary: A carbon-to-silicon switch is widely used in drug discovery. However, organosilicon compounds are not naturally occurring, so the development of effective synthetic methods is crucial for expanding their diversity. In this study, we have successfully synthesized a chiral bridged bicyclic silicon scaffold, which provides a new approach for the synthesis of chiral silicon compounds.
Article
Chemistry, Multidisciplinary
Vitor A. Fernandes, Rafaely N. Lima, Yoisel B. Broterson, Meire Y. Kawamura, Radell Echemendia, Alexander F. de la Torre, Marco A. B. Ferreira, Daniel G. Rivera, Marcio W. Paixao
Summary: An efficient strategy combining stereocontrol of organocatalysis with diversity-generating character of multicomponent reactions was used to produce structurally unique, tetrasubstituted cyclopentenyl frameworks. This approach yielded a diversity of structurally complex compounds with high stereoselectivity and moderate to high yields, including peptidomimetics and natural product hybrids.
Article
Chemistry, Organic
Qiuyu Li, Rui Pan, Meihui Wang, Hequan Yao, Aijun Lin
Summary: In this study, ligand-controlled, palladium-catalyzed asymmetric [4+4] and [2+4] cycloaddition reactions of benzofuran-derived azadienes were developed. Different chiral ligands were utilized to synthesize various cyclic compounds with high enantioselectivity.
Article
Chemistry, Organic
Aureilien Dupeux, Emilie Gentilini, Veironique Michelet
Summary: Gold-catalyzed Prins-type cyclizations are a fascinating approach for synthesizing complex molecules with excellent stereochemistry. Researchers have developed a new and efficient system for this reaction, achieving yields up to 89% in 13 examples. They also reported the first enantioselective version of a gold-catalyzed Prins-type cyclization using a chiral TADDOL-based Au(I) phosphonite complex, yielding highly enantiomerically enriched products (>99% ee) after crystallization.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Harrison M. Snodgrass, Dibyendu Mondal, Jared C. Lewis
Summary: In this study, a variant of the flavin-dependent halogenase RebH was engineered to catalyze site- and atroposelective halogenation reactions of 3-aryl-4(3H)-quinazolinones. The directed evolution process used a combination of mutagenesis, substrate walking, and screening methods to improve the conversion and selectivity of the enzyme. The resulting variant showed high activity and selectivity on multiple substrates, and computational modeling was used to understand the effects of key mutations on substrate binding. This study demonstrates the potential of flavin-dependent halogenases for atroposelective catalysis and highlights the versatility of RebH in accepting structurally diverse substrates for enantioselective synthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Yazhou Lou, Junqiang Wei, Mingfeng Li, Ye Zhu
Summary: This study reports an asymmetric reaction that establishes chirality at a remote position by using electrostatic steering to exert stereocontrol on the substrate. It demonstrates the achievement of precise long-range stereocontrol through ionic substrate-ligand interactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Pier Alexandre Champagne
Summary: The first catalytic intermolecular desymmetrization of azetidines was reported in 2015, and Density Functional Theory calculations were used to uncover the mechanism and high enantioselectivity. The reaction proceeds through bifunctional activation of the azetidine nitrogen and the thione tautomer of the 2-mercaptobenzothiazole nucleophile. The selectivity is driven by the ability of the substrates to fit into the chiral catalyst pocket based on primary orbital interaction requirements.
Article
Chemistry, Multidisciplinary
Hong-Cheng Shen, Ying Chen, Ying Zhang, He-Ming Jiang, Wen-Qian Zhang, Wen-Ao Li, Mostafa Sayed, Xinhao Zhang, Yun-Dong Wu, Liu-Zhu Gong
Summary: The study demonstrates a nickel-catalyzed enantioselective desymmetrizing aza-Heck cyclization, utilizing a pentafluorobenzoyl leaving group and chiral pybox ligand, with a competitive E2-like pathway and beta-H elimination at the enantioselectivity determining step.
Review
Chemistry, Multidisciplinary
Bing Xu, Quanpu Wang, Chao Fang, Zhan-Ming Zhang, Junliang Zhang
Summary: This review summarizes the latest advancements in enantioselective palladium-catalyzed cyclization reactions over the past eleven years. The review is organized into thirteen sections based on the different types of transformations involved. Chiral palladium catalysts have shown outstanding features in promoting a plethora of enantioselective cyclization reactions, providing convenient access to structurally diverse chiral carbo- and hetero-cycles.
CHEMICAL SOCIETY REVIEWS
(2023)
Article
Chemistry, Physical
Pim R. Linnebank, David A. Poole, Alexander M. Kluwer, Joost N. H. Reek
Summary: The use of data driven tools to predict the selectivity of homogeneous catalysts has been studied, but the use of substrate descriptors to rationalize the catalytic outcome is relatively unexplored. In this study, the regioselectivity of the hydroformylation reaction of terminal alkenes was predicted with high accuracy using the ?C-13 NMR shift and I-CC stretch descriptors for a non-encapsulated rhodium based catalyst. However, the use of substrate descriptors for an encapsulated catalyst appeared more challenging.
FARADAY DISCUSSIONS
(2023)
Article
Environmental Sciences
Noman Shakoor, Muhammad Adeel, Imran Azeem, Muhammad Arslan Ahmad, Muhammad Zain, Aown Abbas, Muzammil Hussain, Yaqi Jiang, Pingfan Zhou, Yuanbo Li, Ming Xu, Yukui Rui
Summary: We conducted a meta-analysis of recent literature to investigate the impact of different lithium sources and levels on plant species under different growth conditions. The toxic effects of lithium exposure in plants varied depending on the medium, with more negative responses observed in hydroponic systems compared to soil and foliar application. The source materials of lithium also influenced its toxic effects, with lithium chloride negatively affecting parameters related to plant germination and root biomass, while lithium nitrate had more negative effects on shoot biomass. The dosage of lithium also played a role, with concentrations below 50 mg/L significantly influencing plant physiological indicators, while concentrations between 50-500 mg/L affected biochemical parameters. The dose-response relationship (EC50) for different exposure mediums ranged from 24.6-196.7 ppm. The bioaccumulation and trophic transfer of lithium in edible tissues of crops remains unknown and should be investigated in future research.
Article
Engineering, Environmental
Noman Shakoor, Muhammad Adeel, Muhammad Arslan Ahmad, Muzammil Hussain, Imran Azeem, Muhammad Zain, Pingfan Zhou, Yuanbo Li, Ming Xu, Yukui Rui
Summary: This study investigates the effects of lithium on the physiology and metabolites of soybeans. The results show that high concentrations of lithium inhibit soybean growth and development, alter root metabolites, and decrease calcium and magnesium levels. The study also reveals the important roles of vacuoles and cell walls in defending against lithium stress.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Muzammil Hussain, Noman Shakoor, Muhammad Adeel, Muhammad Arslan Ahmad, Haichao Zhou, Zhiyong Zhang, Ming Xu, Yukui Rui, Jason C. White
Summary: Nanoscale materials can enhance plant growth and control phytopathogens by altering the diversity and composition of plant microbiota. Understanding the complex interactions between nanomaterials, host plants, pathogens, microbiome, and environment is crucial for using nanomaterials in microbiome engineering to improve plant growth and disease protection.
Article
Engineering, Electrical & Electronic
Muhammad Khalid, Samran Naseer, Muhammad Suleman Tahir, Iqra Shafiq, Khurram Shahzad Munawar, Sara Figueiredo de Alcantara Morais, Ataualpa A. C. Braga
Summary: Current research focuses on using non-fullerene organic materials for the development of nonlinear optical (NLO) technology. Seven new derivatives (DTPSD2-DTPSD8) were designed based on a reference compound (DTPSR1) by incorporating various acceptor moieties. Computational analysis was performed to evaluate the molecular properties and optical characteristics of these compounds. The results showed promising similarities between the derivatives and the reference molecule, indicating their potential applications in telecommunications, data storage, and optical poling.
OPTICAL AND QUANTUM ELECTRONICS
(2023)
Review
Soil Science
Pingfan Zhou, Liuwei Wang, Jing Gao, Yaqi Jiang, Muhammad Adeel, Deyi Hou
Summary: Nanoplastics (NPs) are accumulating in the soil environment and pose serious consequences for ecosystems and human health. This review provides a summary of current studies on NP-plant interactions, focusing on uptake mechanisms and phytotoxicity of NPs. NPs can be taken up by plant roots, transported throughout the plant, and negatively impact plant growth and development. The potential mechanism of NP-plant interactions and future perspectives are also discussed.
SOIL USE AND MANAGEMENT
(2023)
Article
Polymer Science
Muhammad Nadeem Arshad, Iqra Shafiq, Muhammad Khalid, Mohammad Asad, Abdullah M. Asiri, Maha M. Alotaibi, Ataualpa A. C. Braga, Anish Khan, Khalid A. Alamry
Summary: Currently, polymer organic solar cells (POSCs) are widely used due to their low-cost power conversion efficiencies (PCEs). In this study, a series of photovoltaic materials incorporating selenophene units were designed to enhance the photovoltaic behavior of POSCs. The results showed that the addition of selenophene units led to a reduction in energy gaps, broader absorption wavelength, and larger charge transference rate compared to the reference compound. The compounds were found to be efficient POSCs materials with significant efficacy, which may encourage further experimental synthesis.
Article
Engineering, Environmental
Edson Leonardo Scarpa de Souza, Tomaz Henrique Duarte Chorro, Carlos Roque Duarte Correia
Summary: Arenediazonium salts are important aromatic organic compounds used as building blocks in academia and industry. Tetrafluoroborate arenediazonium salts are generally stable at room temperature, but those containing heteroatoms in the aromatic moiety can be problematic and unstable. This study evaluated the thermal stability and potential hazards of 58 common arenediazonium tetrafluoroborate salts, providing guidance for their safe use and handling in organic synthesis.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Multidisciplinary Sciences
Iqra Shafiq, Muhammad Khalid, Muhammad Adnan Asghar, Rabia Baby, Ataualpa A. C. Braga, Saad M. Alshehri, Sarfraz Ahmed
Summary: In this study, D-p-A-p-D form chromophores were designed and applied in organic solar cells. The analysis of various characteristics showed that these chromophores have suitable band gaps and significant bathochromic shifts. The analysis of frontier molecular orbitals revealed effective charge transfer from donor to acceptor. Overall, these tailored chromophores can be considered efficient compounds for promising organic solar cells.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Muhammad Khalid, Zubaria Saeed, Iqra Shafiq, Muhammad Adnan Asghar, Ataualpa Albert Carmo Braga, Saad M. Alshehri, Muhammad Safwan Akram, Suvash Chandra Ojha
Summary: In this work, non-fullerene based derivatives (DTCD2-DTCD8) with D1-p-D2-p-A architecture were designed to investigate their nonlinear optical (NLO) behavior by altering the terminal acceptor group of a reference molecule (DTCR1). The influence of peripheral acceptor and donor sites on the designed configuration for optical communication and electronic response was examined using DFT based calculations. The calculated results showed that all the derivatives (DTCD2-DTCD8) exhibited significant NLO behavior, with DTCD8 demonstrating the highest dipole moment, linear polarizability, first hyperpolarizability, and second hyperpolarizability due to its lowest energy gap value.
JOURNAL OF SAUDI CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Muhammad Khalid, Rabia Maqsood, Iqra Shafiq, Rabia Baby, Muhammad Adnan Asghar, Sarfraz Ahmed, Saad M. M. Alshehri, Ataualpa A. C. Braga
Summary: The research aims to investigate the nonlinear optical (NLO) properties of novel benzodithiophene-based donor-acceptor compounds through structural modulation. The optimized geometries of the compounds were analyzed for UV-Vis absorption, natural population analysis, NLO, frontier molecular orbitals, and natural bond orbitals. The energy difference between the tailored compounds and the reference compound was found to be small, with BDTD3 showing the smallest difference. BDTD3 exhibited the highest value of λ(max) and the highest values of β(tot) and γ(tot), indicating its potential as a candidate for nonlinear optics.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Rima D. Alharthy, Nadeem Ahmed, Saman Mubarak, Muhammad Yaqub, Muhammad Khalid, Iqra Shafiq, Muhammad Adnan Asghar, Ataualpa Albert Carmo Braga, Zahid Shafiq
Summary: A series of sensors, SM-1 to SM-3, were designed and synthesized using indole carboxaldehydes and 2,4-dinitrophenyl hydrazine. The synthesis was accompanied by a density functional theory investigation, which revealed a reduction in band gap, a bathochromic shift, and charge transference. SM-3 displayed high selectivity toward F- ions, with a low detection limit and a binding constant of 7.7 x 105.
Article
Chemistry, Multidisciplinary
Rima D. Alharthy, Nadeem Ahmed, Saman Mubarak, Muhammad Yaqub, Muhammad Khalid, Iqra Shafiq, Muhammad Adnan Asghar, Ataualpa Albert Carmo Braga, Zahid Shafiq
Summary: A new series of sensors (SM-1 to SM-3) were synthesized using indole carboxaldehydes and 2,4-dinitrophenyl hydrazine. The deprotonated chromophores exhibited a smaller band gap and a red shift compared to the neutral sensors. Charge transfer from indole to dinitrophenyl hydrazine was observed. Sensor SM-3 showed high selectivity for F- ions, while SM-1 and SM-2 responded to both F- and CN- ions.
Article
Chemistry, Physical
Muhammad Khalid, Shahzad Murtaza, Madiha Bano, Iqra Shafiq, Rifat Jawaria, Ataulapa A. C. Braga
Summary: Through quantum chemical investigation, a series of highly efficient fullerene-free organic solar cells were designed, showing improved charge transfer and open circuit voltage by modifying the acceptor structure, as well as enhanced absorption spectrum.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2024)
Article
Chemistry, Multidisciplinary
Muhammad Sagir, Kalsoom Mushtaq, Muhammad Khalid, Mashal Khan, Muhammad Bilal Tahir, Ataualpa A. C. Braga
Summary: In this study, seven non-fullerene compounds were designed and their nonlinear optical properties were explored. Quantum chemical methods were used to analyze and evaluate the materials, and ATTD3 was found to be the best possibility for NLO materials.
Article
Chemistry, Multidisciplinary
Saba Abid, Muhammad Khalid, Muhammad Sagir, Muhammad Imran, Ataualpa A. C. Braga, Suvash Chandra Ojha
Summary: A series of indacenodithiophene-based derivatives were designed and studied for their nonlinear optical (NLO) behavior. Quantum chemical calculations were performed to analyze the electronic, structural, and optical properties of these derivatives. The results showed that the structural modifications of the derivatives significantly influenced their energy gaps and absorption spectra. TNPD5 exhibited the lowest energy gap and highest softness among the derivatives. Furthermore, TNPD5 showed the highest first and second hyper-polarizabilities. These findings suggest that the end-capped substituents play a crucial role in enhancing the NLO response of these derivatives, making them potential efficient NLO materials.
