Article
Chemistry, Multidisciplinary
Matthew J. J. Genzink, Matthew D. D. Rossler, Herman Recendiz, Tehshik P. P. Yoon
Summary: Chiral acid catalysts are shown to promote highly selective visible-light photocycloadditions, leading to the synthesis of truxinate natural products. This general approach allows for the efficient synthesis of dimeric and pseudodimeric cyclobutane natural products with excellent enantioselectivity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Hao-Zeng Wu, Zhong-Shan Teng, Yu-Xin Ke, Yu Zou, Ping Gao, Yue Li, Cheng-He Zhou, Zhong-Lin Zang
Summary: Tuning the electronic structure of protecting groups on the nitrogen atom of substrates has emerged as an effective strategy for achieving tandem trifluoromethylation/C(sp(2))-H annulation using Langlois' reagent as the CF3 source for electrochemical synthesis of functionalized tetrahydroquinolines and dihydroquinolinones.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Seung Hoon Lee, Hyung Min Chi
Summary: In this study, a transition-metal-free, practical one-pot synthesis of C4-aryl-substituted tetrahydroquinolines from simple anilines and readily accessible propargylic chlorides was developed. The key interaction was the activation of the C-Cl bond by 1,1,1,3,3,3-hexafluoroisopropanol, which allowed for C-N bond formation under an acidic medium. Demonstrating the synthetic utility, the total syntheses of aflaquinolone F and I were accomplished.
Article
Chemistry, Organic
Fatima Almetwali, Jacques Rouden, Jerome Blanchet
Summary: This study developed novel boronic acids for catalyzed amide synthesis. The Lewis acidity of the boronic acids was estimated using computational techniques, and the increase in catalytic activity was confirmed with kinetic data. A set of newly developed catalysts were found, which showed superior efficacy in the coupling reaction of acids and amines.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Yuli He, Jiawei Ma, Huayue Song, Yao Zhang, Yong Liang, You Wang, Shaolin Zhu
Summary: In this work, a highly regio- and enantioselective Ni-catalysed migratory hydroarylation relay process has been achieved with the combination of two simple ligands, providing direct access to a wide range of structurally diverse chiral 1,1-diarylalkanes. The value of this strategy was further demonstrated by the Ni-catalysed migratory asymmetric 1,3-arylboration.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Applied
Zhuang Li, Xiang Bai, Xian-Yong Wei, Yierxiati Dilixiati, Zi-Chun Fan, Qian-Qian Kong, Li Li, Jia-Hao Li, Kun-Lang Lu, Ji Zhao, Xiao-Qi Zhang, Zhi-Min Zong, Hong-Cun Bai
Summary: This study reports a strategy for directly cleaving the C-ar-C-alpha and C-beta-O bonds in pine lignin over a solid acid to produce guaiacol. The guaiacol yield in a 90% methanol aqueous solution is 18.2 wt%, which is 5.6 wt% higher than that in methanol. The reaction pathway is proposed based on controlled experiments and density functional theory, showing the relationship between deacetylation, C-alpha=O bond formation, and C-ar-C-alpha bond cleavage.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Hoimin Jung, Mannkyu Hong, Marianna Marchini, Marco Villa, Philipp S. Steinlandt, Xiaoqiang Huang, Marcel Hemming, Eric Meggers, Paola Ceroni, Jiyong Park, Mu-Hyun Baik
Summary: The mechanism of [2 + 2] cycloadditions activated by visible light and catalyzed by bis-cyclometalated Rh(iii) and Ir(iii) photocatalysts was investigated. Experimental observations show that the Rh-based photocatalyst produces excellent yield and enantioselectivity, whereas the Ir-photocatalyst yields racemates. Two different mechanistic features were found to compete with each other.
Article
Chemistry, Physical
Joshua Clarke, Youngran Seo, Michel R. Gagne, Trandon A. Bender
Summary: This perspective discusses the key lessons learned from a program aiming to selectively deoxygenate cellulose-derived carbohydrates, with a focus on noneliminative mechanisms and the use of fluoroaryl borane catalysts. The control of substrate and catalyst over the deoxygenation process is crucial, and the lessons from this catalysis program can be applied to other important problems in catalysis and selectivity.
Article
Chemistry, Multidisciplinary
Yating Dai, Shuangshuang Liang, Guangkuo Zeng, Hongchun Huang, Xiaowei Zhao, Shanshan Cao, Zhiyong Jiang
Summary: This article presents a novel protocol based on chiral hydrogen-bonding catalytic strategy for converting electron-rich olefins to acceptors, and successfully carries out asymmetric photocycloadditions. The method is effective for electron-neutral olefins and allows the construction of all-carbon quaternary stereocentres with structurally similar aryl substituents.
Article
Chemistry, Organic
Jibin Li, Zheng Liang, Yuzhi Ren, Jian Gao, Ding Du
Summary: A new class of functionalized gem-difluorocyclopropanes bearing acyl groups was synthesized via the N-heterocyclic carbene catalyzed difluorocyclopropanation of alkenes with aldehydes and CF2Br2. This reaction involves a cascade three-component radical relay/intramolecular cyclization process. The protocol features metal- and photocatalyst-free reaction conditions, readily accessible starting materials, good functional group tolerance, and easy scalability. Moreover, this strategy is appealing to pharmaceutical chemistry because it is potentially useful in constructing and modifying bioactive molecules via late-stage functionalization.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Yao Zhang, Jiawei Ma, Jian Chen, Lingpu Meng, Yong Liang, Shaolin Zhu
Summary: By synergistically combining a known chain-walking ligand and a simple asymmetric cross-coupling ligand with the nickel catalyst, enantioen-riched alpha-aryl alkylboronates could be rapidly obtained as versatile synthetic intermediates through this formal asymmetric remote C(sp(3))-H arylation process.
Article
Chemistry, Physical
Christopher C. McAtee, Daniel J. Nasrallah, Ho Ryu, Michael R. Gatazka, Rory C. McAtee, Mu-Hyun Baik, Corinna S. Schindler
Summary: We describe a regioselective Lewis-acid-catalyzed method for the synthesis of highly functionalized cyclopentadienes incorporating diverse subunits. Insightful studies suggest that the mechanism involves Lewis-acid-catalyzed cycloadditions followed by stepwise oxetane fragmentation, resulting in the formation of functionalized cyclopentadienes. This work provides new insights into the design of catalytic carbonyl-olefin metathesis reactions.
Article
Chemistry, Organic
Zi-Biao Zhao, Jie Wang, Zhou-Hao Zhu, Mu-Wang Chen, Yong-Gui Zhou
Summary: A biomimetic asymmetric reduction method for 2-functionalized quinolines using the chiral and regenerable NAD(P)H model CYNAM has been successfully developed, providing chiral 2-functionalized tetrahydroquinolines with up to 99% ee. By utilizing this method as a key step, a chiral and potent opioid analgesic containing a 1,2,3,4-tetrahydroquinoline motif was synthesized with high overall yield.
Article
Chemistry, Multidisciplinary
Lydia Cox, Yuxiang Zhu, Philip J. Smith, Kirsten E. Christensen, Mireia Sidera Portela, Timothy J. Donohoe
Summary: A Ti(Oi-Pr)(4)-promoted 5- or 6-endo-trig cyclization for the synthesis of nitrogen heterocycles is presented. The use of HFIP as a key solvent enables the stereoselective formation of di- and tri-substituted pyrrolidines and piperidines while simultaneously forming a new C-C bond. The process involves the generation of a cationic intermediate from an allylic or benzylic alcohol and leads to the simultaneous generation of both a C-C and a C-N bond in a single step. Notably, different substituents on a nucleophilic amine yield either 2,3-trans- or 2,3-cis-substituted heterocycles. Lastly, enantiopure products can be obtained by using readily available enantiopure acyclic starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ana M. Martinez-Gualda, Pablo Domingo-Legarda, Thomas Rigotti, Sergio Diaz-Tendero, Alberto Fraile, Jose Aleman
Summary: The asymmetric synthesis of chiral polycyclic ethers is achieved through an intramolecular [2+2] photocycloaddition, utilizing a photocatalytically active iminium ion-based charge transfer complex under visible light irradiation. This method enables stereocontrolled [2+2] photocycloaddition, yielding tricyclic products with good enantiomeric ratios.
CHEMICAL COMMUNICATIONS
(2021)
