Article
Chemistry, Organic
Shuai Fan, Tai Jiang, Tinghong Lv, Jian Liu, Xiaolei Wang
Summary: This article presents an efficient synthesis method for the complex nucleoside antibiotic ezomycins core structure from diacetone-d-allose, using a ruthenium-catalyzed asymmetric allylic etherification and a de novo carbohydrate synthesis based on the diastereoselective Henry reaction. This method overcomes challenges such as introducing multiple functional groups and consecutive stereocenters with high selectivity, allowing rapid preparation of disaccharides and paving the way for the total synthesis of ezomycins.
Article
Chemistry, Organic
Jiaming Ao, Xiaoya Zhao, Siai Zhou, Yajing Guo, Guoqing Wang, Sixian Fang, Xuewen Yao, Yuhua Liu, Akihiro Ishiwata, Katsunori Tanaka, Feiqing Ding, Hui Cai
Summary: The core repeating tetrasaccharide unit of the prevalent Streptococcus pneumoniae 23F capsule polysaccharide was synthetized through a stereocontrolled reaction mediated by a zinc cation. The successful synthesis was achieved by using a specific reaction pathway and the directing effect of the metal ion.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Alexander Horn, Uli Kazmaier
Summary: The macrolactonisation of a novel heptapeptide precursor with PyAOP has proven to be an excellent method for preparing the cyclic depsipeptide core of callipeltin A. The high yield and selectivity of the individual building blocks and the successive coupling reactions allowed for the straightforward synthesis of the linear heptapeptide from tyrosine 6, with a 27% overall yield over 12 steps.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Freya Taday, Ryan Cairns, Adam O'Connell, Elaine O'Reilly
Summary: A hybrid bio-organocatalytic cascade method was developed for the synthesis of 2-substituted piperidines, utilizing a transaminase to generate a key reactive intermediate for the Mannich reaction.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Eilidh G. Young, Phillip S. Grant, Daniel P. Furkert, Margaret A. Brimble
Summary: Lycibarbarines A-C are spirocyclic alkaloids with a unique tetracyclic framework. The first total syntheses of lycibarbarines A-C were achieved over 10 steps. The spiroketal unit of lycibarbarines A-C exhibits unusually high resistance to acid-mediated isomerization and epimerization.
Article
Chemistry, Organic
Lisi Yuan, Ya Fang, Zhaobo Zhou, Tinghong Lv, Yingpeng Su, Jian Liu, Xiaolei Wang
Summary: This Letter describes a highly diastereoselective synthesis method for C-hydroxymethine glycosides from glycal anomers using an achiral N-heterocyclic carbene-copper catalyst. The diastereoselectivity is controlled by both the stereocenter of the substrate and the chirality of the N-heterocyclic carbene-copper complex, independent of the stereochemistry of C5 and the anomeric position. This approach allows for the production of a diverse range of C-hydroxymethine glycosides using versatile glycals and various functionalized aldehydes.
Article
Chemistry, Organic
Dhiman Saha, Gour Hari Mandal, Rajib Kumar Goswami
Summary: A convergent route has been developed for the asymmetric total synthesis of potent anticancer polyketide natural product amphirionin-2, with key features including Sharpless asymmetric dihydroxylation, cycloetherification, Wittig olefination, Julia-Kocienski olefination, and Crimmins propionate aldol reaction after the proposed structures of amphirionin-2 were revised based on a recent report.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Stephen G. Davies, Ai M. Fletcher, Sean M. Linsdall, Paul M. Roberts, James E. Thomson
Summary: The synthesis of various loline alkaloids was achieved through a series of reactions. The C(7) and C(7a) stereogenic centers were formed by conjugate addition and subsequent oxidation and exchange reactions. The remaining C(1) and C(2) stereogenic centers were formed through a Mannich-type reaction. The synthesis was completed by forming the 2,7-ether bridge and further manipulations.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
David A. Candito, Yingchun Ye, Ryan Quiroz, Michael H. Reutershan, David Witter, Surendra B. Gadamsetty, Hongming Li, Josep Sauri, Sebastian E. Schneider, Yu-hong Lam, Rachel L. Palte
Summary: This study presents a flexible and robust strategy for accessing tetrahydrofuro[3,4-b]furan nucleoside analogues in the context of a PRMT5 inhibitor program. Compound 1.1-C was synthesized and demonstrated to be a potent PRMT5 inhibitor, laying the groundwork for the development of new inhibitors and nucleoside chemical matter for drug discovery programs.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Yuta Miyamoto, Arihiro Iwasaki, Haruka Fujimura, Chihiro Kudo, Naoaki Kurisawa, Osamu Ohno, Kiyotake Suenaga
Summary: Caldorazole, a novel polyketide, was isolated from a marine cyanobacterium in 2022. Despite lacking chiral centers, it exhibits potent inhibitory activity against mitochondrial respiratory chain complex I. To study its structure-activity relationship, we accomplished the first total synthesis of caldorazole using a convergent synthetic route, aiming to establish a method for obtaining caldorazole without relying on biological resources.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jicheng Wu, Peijing Jia, Rositha Kuniyil, Peng Liu, Weiping Tang
Summary: In this study, we report an efficient method for the stereoselective synthesis of challenging α-linked glycoconjugates using a Rh-II/chiral phosphoric acid (CPA)-cocatalyzed dynamic kinetic anomeric O-alkylation. By exploring various parameters of the cocatalytic system, we achieved excellent anomeric selectivity, excellent diastereoselectivity, broad substrate scope, and high efficiency for this glycosylation reaction. DFT calculations suggested that the anomeric selectivity was determined by steric interactions between the C2-carbon of the carbohydrate and the phenyl group of the metal carbenoid, while diastereoselectivity at the newly generated stereogenic center was influenced by π-π interactions with the C2-OBn substituent on the carbohydrate substrate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Zhizhou Chen, Xiangwen Kong, Shengtong Niu, Shuang Yang, Jinggong Liu, Bolai Chen, Benlong Luo, Changyu Zhou, Chenglin Ding, Xinqiang Fang
Summary: Asymmetric construction of cyclopentenones using N-Heterocyclic carbene catalysis with enals and alpha-diketones has been achieved, yielding a series of highly functionalized cyclopentenones in a highly diastereo- and enantioselective manner. The protocol is tolerant of substrates with both aromatic and aliphatic groups, and further transformations of the products have led to a range of value-added molecules.
Article
Chemistry, Organic
Kevin M. Hoang, Xiaoying Zheng, Seth B. Herzon
Summary: Recent research in carbohydrate chemistry has focused on the controlled synthesis of O-glycosides derived from acceptors with multiple hydroxyl substituents. However, there are few examples of the synthesis of O-glycosides with free hydroxyl substituents on the donor reagent. This study presents a new strategy for the synthesis of O-glycosides with free hydroxyl substituents using an umpolung glycosylation strategy.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Intzar Ali, M. V. Kamala Lakshmi, Ramu Sridhar Perali
Summary: The Mislow-Evans rearrangement was utilized to construct digitoxose-derived glycals used in the synthesis of cardenolides digitoxin, digoxin, and gitoxin. The scalability of the trisaccharide synthesis was demonstrated by performing reactions on a multigram scale. Glycosylation reactions between the synthesized digoxin glycal donor and aglycons digoxigenin and gitoxigenin yielded novel cardenolide derivatives.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Liselle Atkin, Angus Robertson, Jonathan M. White, Mark A. Rizzacasa
Summary: The total synthesis of viridiofungins A and B via beta-lactone 3 in 13 steps is described, with key steps including an HF-mediated rearrangement, olefin cross metathesis while suppressing isomerization, and a novel beta-lactone ring opening. Deprotection yielded either viridiofungin A or B in high yield.
Article
Crystallography
Ashraf A. Aly, Martin Nieger, Stefan Braese, Momtaz E. M. Bakheet
Summary: The X-ray structure analyses of four compounds were conducted, revealing strong intramolecular hydrogen bonds that play significant roles in their crystal packing.
JOURNAL OF CHEMICAL CRYSTALLOGRAPHY
(2023)
Article
Chemistry, Organic
Jehan Y. Al-Humaidi, A. A. Nayl, Mohamed M. Abdalla, Sobhi M. Gomha
Summary: This study synthesized and tested the in-vivo activity of different compounds, and found that triazolo-tetrazine derivatives have excellent anticonvulsant and CNS-depressant activities. Further structure-activity relationship studies demonstrated that electron-releasing groups increase activity while electron-withdrawing groups decrease activity.
POLYCYCLIC AROMATIC COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
N. Maximilian Bojanowski, Aleksandra Vranic, Vincent Hahn, Pascal Rietz, Tobias Messer, Julian Brueckel, Christopher Barner-Kowollik, Eva Blasco, Stefan Braese, Martin Wegener
Summary: Recent studies have introduced a new generation of photoinitiators for 3D laser nanoprinting, replacing two-photon absorption with two-step absorption. This can now be achieved using inexpensive blue laser diodes instead of expensive femtosecond laser systems. Additionally, researchers are exploring alternative photoinitiators that can be excited by one-color two-step absorption and be de-excited by a different laser color.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Chun Li, Henrik Schopmans, Lukas Langer, Stefan Marschner, Abhinav Chandresh, Jochen Buerck, Youichi Tsuchiya, Adachi Chihaya, Wolfgang Wenzel, Stefan Braese, Mariana Kozlowska, Lars Heinke
Summary: Researchers have successfully prepared a crystalline film based on porphyrin with chiral properties and demonstrated excellent optoelectronic performance. By assembling in a metal-organic framework film, the porphyrin core becomes twisted and chiral. The close packing and crystalline order of the porphyrin cores in the film result in outstanding optoelectronic properties. Through exciting the Soret band of porphyrin, efficient photoconduction with a high On-Off ratio is achieved. Moreover, handedness-dependent circularly-polarized-light photoconduction is obtained. The combination of assembly-induced chirality with the rich porphyrin chemistry opens up possibilities for organic materials with exceptional chiral and optoelectronic properties.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Editorial Material
Chemistry, Multidisciplinary
Zahid Hassan, Stefan Braese
Summary: Engineering novel micro-/nanoscale systems and devices based on supramolecular assembly has tremendous potential, but controlling the size, shape, and arrangements without templates remains a challenge.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Hannes Kuehner, Louis Leyen, Zahid Hassan, Christof Woell, Stefan Brase
Summary: In this report, a modular synthesis approach towards a new series of non-centrosymmetric, dipolar 4,4'-bipyridines was described. The selective substitution on only one pyridyl motif that could contain electron-donating or electron-withdrawing groups causes electronic/steric effects on one nitrogen atom in 4,4'-bipyridines. This synthetic protocol was further applied to prepare azo-functionalized asymmetric bipyridines and non-centrosymmetric 4,4'-bipyridine N oxide scaffolds.
Article
Materials Science, Multidisciplinary
Ilona Wagner, Simon Spiegel, Julian Brueckel, Matthias Schwotzer, Alexander Welle, Martina H. H. Stenzel, Stefan Braese, Salma Begum, Manuel Tsotsalas
Summary: Surface engineering of MOF NPs using dynamic modification strategies enables the tailoring of PEG-grafted MOF NPs with improved colloidal stability and high dispersity, while maintaining their morphology and lattice crystallinity. The PEG-grafted MOF NPs show reduced adsorption of HSA protein compared to uncoated ones, indicating the potential for reducing nonspecific interactions and introducing targeting moieties for specific interactions. This approach expands the applications of colloidal MOF NPs in biologically relevant fields.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2023)
Article
Biochemistry & Molecular Biology
Alaa A. Hassan, Ashraf A. Aly, Mohamed Ramadan, Nasr K. Mohamed, Bahaa G. M. Youssif, Hesham A. M. Gomaa, Stefan Braese, Martin Nieger, Amal S. Abd El-Aal
Summary: The diastereoselective reaction between N,N''-1,omega-alkanediylbis[N '-organylthiourea] derivatives and 2,3-diphenylcyclopropenone in refluxing ethanol resulted in the formation of two enantiomers of 3-substituted-1-[2-(5)-3-substituted-4-benzyl-5-oxo-4-phenyl-2-thioxoimid-azolidin-1-yl]ethyl/propyl-5-benzyl-5-phenyl-2-thioxoimidazolidin-4-ones. The isolated compounds were characterized using various techniques, including NMR, IR, mass spectra and elemental analyses, and their structures were elucidated using X-ray crystallography. The tested compounds exhibited significant antiproliferative activity as well as EGFR inhibitory effects, with compound 4c (R = allyl, n = 3) showing the most potent antiproliferative effect and the highest inhibitory effect on EGFR.
MOLECULAR DIVERSITY
(2023)
Article
Materials Science, Multidisciplinary
Mirella Wawryszyn, Robin Wilhelm, John Kim, Xiaoyang Zhong, Jeffery E. Raymond, Richard Thelen, Vanessa Trouillet, Matthias Schwotzer, Stefan Braese, Do Hoon Kim, Nicholas L. Abbott, Joerg Lahann
Summary: In the past decade, the phosphorescence of metal-free confined polymer structures has gained attention due to their sustainability, low toxicity, and usage in sensing applications. This study presents the preparation of a free-standing array of nanofibers and compares their optical properties to films with identical composition. The nanofibers form laterally aligned membranes with a high internal order, hourglass-shaped features, and a long-lived emission in the blue region. This research is significant as it constitutes the first report of long-lived emission from solid-state poly(p-xylylenes) nanofibers, and these controlled polymer arrays have potential applications in organic sensors and optoelectronic devices.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Zhen Zhang, Peng Wu, Ke Wang, Hong Lin, Eduard Spuling, Rongrong Xia, Youjun Wu, Jin Cao, Jianhua Zhang, Bin Wei, Stefan Braese, Zixing Wang
Summary: This study reports the development of white organic light-emitting diodes (WOLEDs) based on platinum complexes with tunable correlated color temperature (CCT). By methylating the ligand, the interaction between Pt(II) complexes was regulated, resulting in adjustable emission and CCT of the WOLEDs. High device performances with high external quantum efficiency and low efficiency roll-offs were achieved using exciplex as a host. Moreover, the CCT of the WOLEDs could be tuned by changing the driving voltages, matching with the daylight spectrum.
ACS MATERIALS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Christin Bednarek, Ute Schepers, Franziska Thomas, Stefan Braese
Summary: With the development of bioconjugation chemistry in the past two decades, particularly highlighted by the Nobel Prize in 2022, the search for new applications has intensified, expanding the possibilities of these simple, specific, and high-yield reactions. The advancement of bioconjugation methods is expected to enhance the field of bioinstructive and bioadaptive materials science in the future. This article discusses the recent developments in coupling various biological entities, such as polysaccharides, oligonucleotides, peptides, and proteins, and explores the impact of bioconjugation reactions in materials science and 3D printing, along with their challenges and requirements.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Frank Tristram, Nicole Jung, Patrick Hodapp, Rasmus R. Schroeder, Christof Woell, Stefan Braese
Summary: This article describes the latest methods of research data management (RDM) in academia, as well as the future prospects of digitalized molecular material workflows. The different elements of an integrated research data management strategy are described, and examples of automated processes are depicted. The use of electronic lab notebooks, data-integration and data-conversion strategies, and the establishment of two platforms for automated synthesis and analysis of materials are highlighted. Two examples of beneficial effects of successful RDM strategies are presented, including a sophisticated tool for data prediction based on machine learning and options for creating community-driven databases.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Biotechnology & Applied Microbiology
Ismail M. Ahmed, Ahmed I. Abd-Elhamid, Ashraf A. Aly, Stefan Braese, AbdElAziz A. Nayl
Summary: Ni2+/Fe3+ LDH, (Ni-Fe-CO3 LDH) with Ni/Fe molar ratio 3.0 was synthesized by co -precipitation for the remediation of chromium (VI) and Alizarine Red-S (ARS-dye). The effects of hydrogen ion concentration, shaking time, ARS-dye and/or Cr(VI) concentration, and adsorbents mass on the process were studied. The results showed that Ni-Fe-CO3 LDH fitted well with the pseudo-second-order model, and Langmuir isotherm had a better adsorption effect on ARS-dye and Cr(VI).
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2023)
Article
Chemistry, Medicinal
Lamya H. Al-Wahaibi, Essmat M. El-Sheref, Alaa A. Hassan, S. Braese, M. Nieger, Bahaa G. M. Youssif, Mahmoud A. A. Ibrahim, Hendawy N. Tawfeek
Summary: 2,3,4-trisubstituted thiazoles 3a-i were successfully synthesized and their structures were determined. These compounds showed excellent antiproliferative activity without exhibiting cytotoxicity. The most potent derivatives, compounds 3a, 3c, 3d, and 3f, demonstrated strong antiproliferative activity against human cancer cell lines and also exhibited potent inhibition against EGFR and BRAF(V600E).
Article
Chemistry, Physical
Lena Pilz, Carsten Natzeck, Jonas Wohlgemuth, Nina Scheuermann, Simon Spiegel, Simon Osswald, Alexander Knebel, Stefan Braese, Christof Woell, Manuel Tsotsalas, Nicholaus Prasetya
Summary: This study presents a novel approach to enhance the properties of polymer membranes from MOFs through crosslinking of the organic linker molecules and subsequent metal-atom removal. The researchers automated the process and used machine learning optimization to ensure reproducibility and high quality of the resulting polymeric membranes. The SURMOF membranes showed improved gas selectivity after crosslinking, and the gas permeance could be restored to its initial condition after removing the metal centers. The resulting polymeric membrane outperforms commercially available polymer membranes for H2/CO2 gas separation.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
