Article
Chemistry, Multidisciplinary
Willi M. Amberg, Erick M. Carreira
Summary: This study presents the total synthesis of the complex molecule (+)-aberrarone using an Au-catalyzed-Sn-mediated cascade reaction, which efficiently closes four rings in the molecule. The method offers a stereoselective approach to synthesizing the natural product with a unique tetracyclic skeleton.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Bastian Jakob, Andreas M. Diehl, Kathrin Horst, Harald Kelm, Georg Manolikakes
Summary: Here we report a palladium-catalyzed asymmetric three-component synthesis of α-arylglycine derivatives. This operationally simple method utilizes glyoxylic acid, sulfonamides, and arylboronic acids as starting materials to obtain α-arylglycine scaffold in good yields and enantioselectivities. The synthesized products can be directly used as building blocks in peptide synthesis.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Harjeet S. Soor, Diego B. Diaz, Katherine I. Burton, Andrei K. Yudin
Summary: The ongoing search for underdeveloped functional group combinations has led to the discovery of alpha-fluorinated aminoalkylboronic acids, a new class of molecules featuring the B-CF linkage. These compounds can be generated through electrophilic fluorination and show stability and unique structural properties.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Jinbin Zhu, Zhenyue Li, Jiaqi Li, Duanshuai Tian, Ronghua Xu, Zhiyong Tan, Zhengwang Chen, Wenjun Tang
Summary: In this report, an efficient rhodium-catalyzed addition of arylboronic acids to N-heteroaryl ketones is established, affording a variety of valuable alpha-heteroaryl alcohols with excellent functional group compatibility. The employment of the WingPhos ligand containing two anthryl groups is crucial for this transformation.
Article
Chemistry, Multidisciplinary
Marko Nesic, David B. Ryffel, Jonathan Maturano, Michael Shevlin, Scott R. Pollack, Donald R. Gauthier Jr, Pablo Trigo-Mourin, Li-Kang Zhang, Danielle M. Schultz, Jamie M. McCabe Dunn, Louis-Charles Campeau, Niki R. Patel, David A. Petrone, David Sarlah
Summary: The collaborative total synthesis of darobactin A, a selective antibiotic against Gram-negative bacteria, has been achieved in a convergent manner using D-Garner's aldehyde and L-serine as starting materials. The synthesis involved 16 steps and three scalable routes were developed to synthesize non-canonical amino acids. The closure of the bismacrocycle was successfully achieved through sequential, halogen-selective Larock indole syntheses, with the cyclization order playing a crucial role in the formation of the desired atropisomer.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Biochemistry & Molecular Biology
Zsuzsanna Feher, Dora Richter, Sandor Nagy, Peter Bagi, Zsolt Rapi, Andras Simon, Laszlo Drahos, Peter Huszthy, Peter Bako, Jozsef Kupai
Summary: This study synthesized six new phase-transfer organocatalysts with different chiral units and crown ethers of varying sizes to catalyze alpha-alkylation and Michael addition reactions, yielding alpha,alpha-disubstituted malonic ester derivatives with excellent yields up to 98%.
Article
Plant Sciences
Oriel A. Sanchez-Velasco, Jorge Saavedra-Olavarria, Daniel A. A. Araya-Santelices, Patricio Hermosilla-Ibanez, Bruce K. Cassels, Edwin G. Perez
Summary: A practical methodology to obtain rare N-Arylcytisine derivatives was reported, utilizing the copper-catalyzed Chan-Lam coupling. The study demonstrated the versatility of the Chan-Lam cross-coupling reaction in the derivatization of natural products.
JOURNAL OF NATURAL PRODUCTS
(2021)
Article
Chemistry, Physical
Cornelius V. Gaertner, Christoph Schneider
Summary: Chiral diphosphane Pd-aqua complexes have been used as efficient cooperative Bronsted acid-base catalysts in asymmetric transformations for the past 25 years. By deprotonating beta-dicarbonyl compounds, they readily form reactive chiral Pd enolates, while a Bronsted acid released from the catalyst activates the electrophile. After a period of dormancy, new developments in the enantioselective synthesis of heterocycles and other useful compounds have recently emerged, utilizing the unique properties of chiral Pd-aqua complexes.
Article
Chemistry, Organic
Hong Kang Teo, Patcharaporn Sae-Lao, Roderick W. Bates
Summary: The structure of preisomide has been confirmed through total synthesis, revealing its unusual N-acyl tetrahydro-1,2-oxazine structure.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Yue Wang, Er-Qing Li, Zheng Duan
Summary: The development of stereodivergent strategies in asymmetric synthesis is crucial for accessing the full range of stereoisomers in products with multiple stereocenters. In this study, a novel P-chirogenic ligand, YuePhos, was developed to achieve precise switching of product stereochemistry in a Pd-catalyzed asymmetric cycloaddition reaction. The method provides an efficient route for the synthesis of pyrrolidines with up to three adjacent stereocenters, with excellent enantiomeric excesses.
Review
Chemistry, Multidisciplinary
Fujie Tanaka
Summary: This article discusses catalysts and catalyst systems that use amino acids, primary, secondary, and/or tertiary amines as key catalytic functional groups to accelerate chemical transformations. It also explores strategies and methods that utilize amine derivatives as catalysts. The understanding of dynamics and kinetic controls in amine-catalyzed reactions has enabled the synthesis of complex molecules in stereocontrolled manners.
Article
Chemistry, Organic
Ni Xiong, Yuanqi Dong, Bin Xu, Yang Li, Rong Zeng
Summary: This study describes a mild protocol for amide formation using nitroarenes as nitrogen sources and an inexpensive iron complex as a catalyst. The method utilizes pH-neutral conditions and avoids the use of strong oxidants or reductants, allowing for tolerance of a wide range of aldehydes and nitroarenes with various functional groups.
Article
Chemistry, Multidisciplinary
Qiqiang Xie, Guangbin Dong
Summary: The Matteson-type reactions have gained increasing interest in organic synthesis, but current tactics mainly focus on carbon chains. In this study, we report the development of the oxa-Matteson reaction, which allows oxygen and carbenoid insertions into alkyl- and arylboronates, leading to the synthesis of boron-substituted ethers. The method demonstrates its utility in the preparation of functional ethers, asymmetric synthesis, and programmable construction of polyethers.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Tshepo Molefe, Dean Barrett, Beatriz Diaz, Roy Forbes, Neil J. Coville
Summary: This study reports on the synthesis and application of osmium nanoparticles supported on and/or encapsulated in hollow carbon spheres for Fischer-Tropsch Synthesis (FTS). It is demonstrated that the interaction between osmium and cobalt has a significant effect on the catalyst activity when loaded together. Proximity of osmium and cobalt leads to higher FTS activity and C5+ production through the primary spillover effect. This study reveals the effect of osmium on FTS catalysts for the first time.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Applied
Liang Xu, Jia Cui, Shan Gao, Jianjun Wang, Jiao Liu, Hongge Jia, Zhuanfang Zhang, Fengjuan Miao, Yu Zang
Summary: Chiral conjugated microporous polymers (CCMPs) containing amide groups were designed and synthesized for the first time as heterogeneous asymmetric catalyst platforms for the stabilization of Pd in asymmetric catalytic synthesis. Four Pd/CCMPs heterogeneous catalysts exhibited efficient catalytic activity and excellent enantioselectivity in the asymmetric Henry reaction, with a wide range of substrates and easy recovery. The Pd/CCMPs composites could be easily recycled and maintained catalytic activity after 3 cycles of reactions.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Biology
Samson Afewerki, Nicole Bassous, Samarah Vargas Harb, Marcus Alexandre F. Corat, Sushila Maharjan, Guillermo U. Ruiz-Esparza, Mirian M. M. de Paula, Thomas J. Webster, Carla Roberta Tim, Bartolomeu Cruz Viana, Danquan Wang, Xichi Wang, Fernanda Roberta Marciano, Anderson Oliveira Lobo
Summary: The engineering of multifunctional bactericidal nanofibers for hernia repair using integrated electrospinning, plasma treatment and direct surface modification strategy shows optimal properties with good bactericidal activity, low inflammatory response, and good biodegradation. These nanofibers also promote collagen and blood vessel formation and tissue growth in vivo.
COMMUNICATIONS BIOLOGY
(2021)
Article
Chemistry, Organic
Guangning Ma, Samson Afewerki, Kaiheng Zhang, Ismail Ibrahem, Armando Cordova
Summary: The study demonstrates the ability of intermolecular cooperative thiourea/oxime hydrogen-bond catalysis to improve and accelerate asymmetric aminocatalysis by achieving highly stereoselective transformations through synergy.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Biophysics
Erlane de Sousa Araujo, Thiago Domingues Stocco, Gustavo Fernandes de Sousa, Samson Afewerki, Fernanda Roberta Marciano, Marcus Alexandre Finzi Corat, Mirian Michelle Machado de Paula, Thiago Ferreira Candido Lima Verde, Mayara Cristina Moreira Silva, Anderson Oliveira Lobo
Summary: Oxygen supply is crucial in cell culture for tissue engineering, and click chemistry offers a versatile approach for engineering hydrogels.
COLLOIDS AND SURFACES B-BIOINTERFACES
(2021)
Article
Chemistry, Applied
Kaiheng Zhang, Xiang Sheng, Luca Deiana, Erik Svensson Grape, A. Ken Inge, Fahmi Himo, Armando Cordova
Summary: This study reveals the impact of solvent on stereoselective intramolecular amidation, and through the combination with density functional theory calculations, achieves control and transformation of the stereoselectivity of delta-lactam formation. The combination of this solvent-dependent stereoselective switch with asymmetric catalysis and cascade reactions enables the synthesis of diverse compounds with fluorine-containing stereocenters adjacent to tertiary stereocenters.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Physical
Zhiyao Zheng, Luca Deiana, Daniels Posevins, Abdolrahim A. Rafi, Kaiheng Zhang, Magnus J. Johansson, Cheuk-Wai Tai, Armando Cordova, Jan-E Backvall
Summary: In this study, an efficient nanocopper-catalyzed Alder-ene reaction of allenynamides is described. Copper nanoparticles were immobilized on amino-functionalized micro-crystalline cellulose. The reaction exhibited solvent-controlled chemoselectivity, leading to the synthesis of pyrrolines and pyrroles. The heterogeneous copper catalyst showed high efficiency and recyclability in the Alder-ene reaction, making it a highly attractive catalytic system from an economic and environmental perspective.
Article
Chemistry, Applied
Samson Afewerki, Guangning Ma, Luca Deiana, Hongli Wu, Genping Huang, Armando Cordova
Summary: The existence of off-cycle catalyst cooperativity in amine/metal combined catalysis is revealed. Experimental and theoretical studies show that dual catalysts can perform off-cycle cooperativity, leading to the formation of stable bicyclo[3.2.0]heptane species that limit the formation of carbocycle products. Insight into this mode of co-catalyst cooperativity sheds new light on the chiral amine/metal co-catalyzed reactions and provides a deeper understanding for future design of improved enantioselective reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Review
Biochemistry & Molecular Biology
Diana Ramirez-Gamboa, Ana Laura Diaz-Zamorano, Edgar Ricardo Melendez-Sanchez, Humberto Reyes-Pardo, Karen Rocio Villasenor-Zepeda, Miguel E. Lopez-Arellanes, Juan Eduardo Sosa-Hernandez, Karina G. Coronado-Apodaca, Ana Gamez-Mendez, Samson Afewerki, Hafiz M. N. Iqbal, Roberto Parra-Saldivar, Manuel Martinez-Ruiz
Summary: This study presents the functions, characteristics, and types of photolyases, their therapeutic and cosmetic applications, and additionally explores some photolyase-producing microorganisms and drug delivery systems.
Review
Chemistry, Multidisciplinary
Samson Afewerki, Ulrica Edlund
Summary: The production of sustainable materials through green chemistry plays a crucial role in transitioning to a more sustainable society. Combined catalysis allows for innovative chemical reactions and material properties that cannot be achieved with a single catalytic cycle or activation mode alone. By combining the quinone-catechol redox reaction with free radical polymerization or oxidative decarboxylation reaction, sustainable lignin-based materials with versatile properties can be engineered. Further exploration and expansion of this concept in material science is envisioned to draw inspiration from successful implementation in organic synthesis.
Article
Chemistry, Multidisciplinary
Samson Afewerki, Ulrica Edlund
Summary: By utilizing the catalytic system of lignin aluminum nanoparticles (AlNPs) and aluminum ions (Al3+), we have successfully developed a sustainable, environmentally adaptable, flame-retardant, conductive, self-healing, and multifunctional organohydrogel. The organohydrogel exhibits excellent performance in thermal stability, adhesive properties, mechanical durability, and various other aspects, showing great potential for applications in various fields.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Luca Deiana, Elham Badali, Abdolrahim A. Rafi, Cheuk-Wai Tai, Jan-E Backvall, Armando Cordova
Summary: This article describes efficient nanogold-catalyzed cycloisomerization reactions of alkynoic acids and allenynamides, resulting in the formation of enol lactones and dihydropyrroles, respectively. The gold nanoparticles were immobilized on thiol-functionalized microcrystalline cellulose and exhibited robust catalytic activity for multiple cycles.
Article
Chemistry, Multidisciplinary
Luca Deiana, Abdolrahim A. Rafi, Jan-E. Baeckvall, Armando Cordova
Summary: Subtilisin integrated artificial plant-cell walls (APCWs) were fabricated by self-assembly with cellulose or nanocellulose as the main component. The resulting APCW catalysts showed excellent catalytic performance for the asymmetric synthesis of (S)-amides. The APCW catalysts could be recycled for multiple cycles without loss of enantioselectivity. The assembled APCW catalysts also cooperated with homogeneous organoruthenium complexes to achieve co-catalytic dynamic kinetic resolution (DKR) of chiral primary amines.
Article
Chemistry, Applied
Rana Alimohammadzadeh, Abdolrahim A. Rafi, Lisa Goclik, Cheuk-Wai Tai, Armando Cordova
Summary: This study reveals the mild and direct organocatalytic esterification of cellulose nanocrystals and nanocellulose-based materials with thioglycolic acid, resulting in functionalized nanocellulose. The introduction of -SH functionality on the nanocellulose surface allows for further selective applications, such as attaching organic catalysts and fluorescent molecules for sensing or using it as a heterogeneous biomimetic reducing agent.
CARBOHYDRATE POLYMER TECHNOLOGIES AND APPLICATIONS
(2022)
Article
Engineering, Biomedical
Gustavo F. Sousa, Samson Afewerki, Dalton Dittz, Francisco E. P. Santos, Daniele O. Gontijo, Sergio R. A. Scalzo, Ana L. C. Santos, Lays C. Guimaraes, Ester M. Pereira, Luciola S. Barcelos, Semiramis J. H. Do Monte, Pedro P. G. Guimaraes, Fernanda R. Marciano, Anderson O. Lobo
Summary: The use of click chemistry to engineer hydrogels allows for the creation of tailor-made hydrogels with desired mechanical and biocompatible properties. In this study, a versatile and facile catalyst-free click chemistry method was developed to generate a novel hydrogel by combining chondroitin sulfate and polyethylene glycol. The resulting hydrogel showed promising results for wound repair and in situ skin tissue engineering applications.
JOURNAL OF FUNCTIONAL BIOMATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Sreevani Vellingiri, Chandrababu Rejeeth, Nipun Babu Varukattu, Alok Sharma, Raju Suresh Kumar, Abdulrahman Almansour, Natarajan Arumugam, Samson Afewerki, Soundarapandian Kannan
Summary: In this study, iron nanoparticles were synthesized from goat blood and used as nanocarriers for drug delivery. The results showed that the nanoparticles had good drug release effects in lung cancer cells and could be used for anticancer treatment. Future research will focus on developing targeted nuclear treatment for cancer and other related diseases using different drug carrier systems.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Physical
Gao Xiao, Huiying Lin, Yiting Lin, Liyin Chen, Xiancai Jiang, Xia Cao, Samson Afewerki, Yujuan Zhang, Weixia Zhang
Summary: Transition metal carbonitrides have been investigated as a potential alternative to precious metal-based catalysts in oxygen reduction reaction (ORR) electrocatalysts. In this study, a highly active and stable ORR catalyst was developed by designing a two-dimensional cobalt-based carbon material. The synthesized Co-C-TA@g-C3N4 heterostructured nanosheet showed outstanding ORR performance, surpassing commercial Pt/C and exhibiting high selectivity with excellent stability and methanol tolerance.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
