Article
Chemistry, Physical
Caitlin Kozack, Stephen J. Tereniak, Jonathan N. Jaworski, Bao Li, David L. Bruns, Spring M. M. Knapp, Clark R. Landis, Shannon S. Stahl
Summary: This study focuses on the impact of benzoquinone on the catalytic activity in palladium(II)-catalyzed allylic acetoxylation. The results indicate that benzoquinone enhances the performance of the catalyst, showing a synergistic effect with Co(salophen) in improving reaction performance. The mechanistic studies suggest that both benzoquinone and oxygen play significant roles in oxidizing Pd(0) to Pd(II), leading to better reaction outcomes.
Article
Electrochemistry
Gabriel J. Mattos, Nikolai Yu. Tiuftiakov, Eric Bakker
Summary: This study demonstrates the successful application of a lipophilic derivative of the redox mediator TEMPO in ion transfer processes at the interface between two immiscible electrolyte solutions. The results show that TEMPO performs well in mediating anion and cation transfer across ion-selective membranes, and has potential applications in this field.
ELECTROCHEMISTRY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Kai Wang, Xiangfeng Lin, Yan Liu, Can Li
Summary: This study presents a novel catalytic asymmetric [4+2] cycloaddition reaction, achieved through direct allylic C-H functionalization with high diastereoselectivities and enantioselectivities to synthesize hydroquinolines.
Article
Materials Science, Paper & Wood
Yuan Zhong, Xueyi Gao, Wanqi Zhang, Xue Wang, Kebing Wang
Summary: In this study, cellulose nanocrystals were prepared from Salix psammophila and carboxyl functional groups were introduced by oxidation. Microscopy observation revealed that the nanocrystals exhibited short rod-like fibers. XPS analysis confirmed the presence of carboxyl groups in the nanocrystals.
Article
Chemistry, Multidisciplinary
Xin Yu, Lingfei Hu, Wolfgang Frey, Gang Lu, Rene Peters
Summary: Catalytic allylic substitution is an important method in asymmetric synthesis to generate C-C bonds with enantioselectivity. However, a common limitation is the formation of allylic substitution products with (E)-configured C=C double bonds. In this study, a planar chiral palladacycle catalyst was used to achieve a diastereospecific reaction outcome, maintaining the C=C double bond geometry of the allylic substrates in highly enantioenriched products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Jeanne Masson-Makdissi, Justin Ching, Cian M. Reid, Mark Lautens
Summary: A dual metal approach enables the use of unsymmetrical diallyl carbonates as viable enolate precursors for allylic alkylation reactions, allowing facile access to various alpha-quaternary allylated aldehydes and ketones. This methodology involves regioselective Pd-catalyzed decarboxylative oxidative addition and Rh-catalyzed isomerization.
Article
Biochemistry & Molecular Biology
Yulia V. Khoroshunova, Denis A. Morozov, Danil A. Kuznetsov, Tatyana V. Rybalova, Yurii I. Glazachev, Elena G. Bagryanskaya, Igor A. Kirilyuk
Summary: Site-directed spin labeling followed by investigation using Electron Paramagnetic Resonance spectroscopy is a powerful technique to study biomolecules. Nitroxides are widely used as spin labels to provide information on structure, dynamics, and functions. The development of nitroxides resistant to biogenic reductants with high spin relaxation time has enabled measurements inside living cells without deep freezing.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Physical
Babak Karimi, Bahareh Ghaffari, Hojatollah Vali
Summary: The study successfully prepared a highly water-dispersible/magnetically separable multi-functional catalyst system by incorporating TEMPO and an imidazolium bromide bearing TEG groups into the Fe3O4@SiO2 core-shell structure. The catalyst showed excellent performance in alcohol oxidation with strong synergistic effect between functionalized components, dual-adjustable selectivity, and recyclability through a double-separation strategy.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Jeanne Masson-Makdissi, Liher Prieto, Xavier Abel-Snape, Mark Lautens
Summary: This study demonstrates the feasibility and advantages of combining two distinct asymmetric transition-metal-catalyzed reactions in one pot, effectively converting simple allyl enol carbonate precursors into enantioenriched cyclic ketones. Despite the challenges in controlling stereoselectivity, the products are obtained with high enantiomeric excesses exceeding 99% ee, surpassing those obtained from individual reactions. Additionally, the one-pot reaction is enantio- and diastereodivergent, allowing easy access to all stereoisomers from the same starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Xin-Meng Chen, Ling Zhu, Dian-Feng Chen, Liu-Zhu Gong
Summary: The chiral indoline-2-carboxylic acid enables a highly enantioselective Catellani-type annulation, directly assembling a diverse range of chiral all-carbon bridged ring systems with high levels of stereochemical control through coordinating orientation to the arylpalladium(II) center identified by control experiments and DFT calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Man-Bo Li, Jie Yang, Ying Yang, Guo-Yong Xu, Gen Luo, Jianping Yang, Jan-E. Backvall
Summary: A solid amino-supported palladium catalyst is used for the diastereoselective construction of alkyne-substituted cyclopentenol compounds in an oxidative domino reaction. This heterogeneous catalyst shows high efficiency, excellent chemoselectivity, and good recyclability, with the chemoselectivity of the domino reactions easily controlled by switching the solvent and catalyst. Asymmetric syntheses and an oxidative carbocyclization-borylation reaction have also been developed based on this heterogeneous palladium catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Multidisciplinary
Xi Wang, Youbin Peng, Ling Zhao, Xiaohong Huo, Wanbin Zhang
Summary: Compared to the stereocontrol of the stereocenter at the allyl unit, asymmetric induction of prochiral nucleophiles is a challenging task in Pd-catalyzed asymmetric allylic substitutions due to the remote distance between the chiral catalyst and the prochiral nucleophile. Extensive efforts have been made to address this challenge through the design of chiral ligands. Recently, synergistic catalysis, including bimetallic catalysis and Pd/organocatalysis, has gained attention for its potential advantages in improving reactivity and selectivity, and providing a simple and unified method for the stereocontrol of prochiral nucleophiles. This review summarizes the history and advances in this field.
SCIENCE CHINA-CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Angelina Yu. Bobrova, Maxim A. Novikov, Roman A. Novikov, Pavel V. Dorovatovskii, Alexander D. Volodin, Alexander A. Korlyukov, Yury V. Tomilov
Summary: The enantioselectivity control in Pd-catalyzed asymmetric amination of 2-fluoroallylic substrates was optimized by using h3-(2-fluorocycloheptenyl)-palladium complexes bearing chiral P,P- and P,N-ligands with various amines. (S)-ButPHOX was identified as the most effective ligand for achieving high enantioselectivity in the formation of 2-fluoroallyl amines and anilines.
MENDELEEV COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Meng-Lan Shen, Pu-Sheng Wang, Liu-Zhu Gong
Summary: A regioselective Pd-catalyzed allylic amination reaction has been developed, which can generate either branched Z-dienyl allylic amines or linear conjugated allylic amines with high levels of regioselectivity from the same substrates by tuning the reaction conditions.
Article
Chemistry, Applied
Hua Wang, He Wang, Lei Li, Xin Wang, Ran Sun, Ming-Dong Zhou
Summary: A ruthenium(II)-catalyzed hydroamination reaction of allenoates with arylamines has been developed, providing a straightforward and efficient approach to synthesize E-allylic amines with high selectivity and atom economy.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
