Article
Chemistry, Multidisciplinary
Guangrong Meng, Liang Hu, Martin Tomanik, Jin-Quan Yu
Summary: Pd-II-catalyzed beta- and gamma-C(sp(3))-H heteroarylation of free carboxylic acids using pyridine-pyridone ligands overcomes limitations in selective functionalization and compatibility with heteroatoms. A sequence of three consecutive C(sp(3))-H activation reactions of pivalic acid constructs diverse quaternary carbon centers containing heteroaryls, offering a valuable tool for breaking new ground in medicinal chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Zhe Zhuang, Shuang Liu, Jin-Tang Cheng, Kap-Sun Yeung, Jennifer X. Qiao, Nicholas A. Meanwell, Jin-Quan Yu
Summary: In this study, a novel C-H functionalization reaction was reported, which utilizes common protecting groups and practical oxidants for the lactamization of tosyl-protected aliphatic amides. The reaction was enabled by a specific ligand and shows mild reaction conditions, good scalability, and the use of convenient oxidants and protecting groups. Further derivatization of the beta-lactam products allows the synthesis of various biologically significant compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Zhe Zhuang, Alastair N. Herron, Jin-Quan Yu
Summary: The development of C(sp(3))-H functionalizations of free carboxylic acids has provided a wide range of versatile reactions, enabling convenient synthesis of cyclic anhydrides using Mo(CO)(6) as a solid CO source and a bidentate ligand. Succinic anhydride products serve as versatile intermediates for introducing various functional groups at the beta position of parent acids, offering a divergent strategy for synthesizing carboxylic acids inaccessible by previous beta-C-H activation reactions. Furthermore, enantioselective carbonylation of free cyclopropanecarboxylic acids has been achieved using a chiral bidentate thioether ligand.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Ruqaya Buhaibeh, Tiphaine Richard, Regis M. Gauvin, Mathieu Sauthier, Clement Dumont
Summary: Hydroxyl groups of industrial grade lignins are esterified using palladium-catalyzed hydroesterification reactions with CO and olefins, fatty esters or 1,3-butadiene. This efficient and salt-free reaction allows the incorporation of aliphatic chains into lignin through ester linkage. The modified lignins with introduced aliphatic chains exhibit altered glass transition temperatures, dependent on the substitution degree of hydroxyl groups and the nature of the introduced chains. Additionally, this catalysis enables the introduction of new reactive functionalities, such as esters or unsaturations, from abundant and/or biobased reactants.
Article
Chemistry, Multidisciplinary
Enrico Bergamaschi, Danijela Lunic, Liam A. McLean, Melissa Hohenadel, Yi-Kai Chen, Christopher J. Teskey
Summary: This study demonstrates, for the first time, the ability to use light to distinguish between ketones and carboxylic acids in more complex molecules. By utilizing different activation modes, a single catalytic system can be used for hydroboration, with chemoselectivity dictated solely by the presence or absence of visible light.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Jenna L. Payne, Zihang Deng, Andrew L. Flach, Jeffrey N. Johnston
Summary: In recent years, enantioselective halolactonization reactions have grown rapidly, but most are only effective in forming smaller rings (6,5,4-membered). The formation of highly selective seven-membered epsilon-lactones is rare and has never been achieved without conformational bias. This study describes the first highly enantioselective 7-exo-trig iodolactonizations of conformationally unbiased epsilon-unsaturated carboxylic acids, using a combination of a bifunctional BAM catalyst, I-2, and I(iii) reagent (PhI(OAc)(2):PIDA).
Article
Chemistry, Multidisciplinary
Jingran Zhang, Ayesha Jalil, Jiaxin He, Zhenyang Yu, Yifu Cheng, Guangchen Li, Yunfei Du, Kang Zhao
Summary: A series of alkoxylated isobenzofuranones were conveniently synthesized through a cascade reaction. The reaction mechanism involves lactonization, aryl migration, and alkoxylation processes, and organocatalytic and chiral reactions were also explored.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Inorganic & Nuclear
Patrick J. Morgan, Graham C. Saunders, Stuart A. Macgregor, Andrew C. Marr, Peter Licence
Summary: A cyclometallated rhodium complex was used as a catalyst for the quantitative nucleophilic fluorination of a range of acyl chlorides to acyl fluorides. The catalyst showed high yields and could be separated, regenerated, and reused. The reaction mechanism was proposed to involve a nucleophilic Rh-F bond based on graphical kinetic analysis and DFT calculations.
Article
Chemistry, Organic
Wenlong Ren, Mingzhou Wang, Jianqiong Guo, Jintao Zhou, Jianxiao Chu, Yuan Shi, Yian Shi
Summary: A regioselective Pd-catalyzed hydrocarboxylation of terminal olefins with HCOOH is described. A wide variety of branched carboxylic acids can be obtained easily under mild reaction conditions with high regioselectivities. The operation of the reaction is simple and does not require handling toxic CO. The ligand and LiCl play important roles in reaction reactivity and selectivity.
Review
Chemistry, Multidisciplinary
Tianyu Li, David A. Harrington
Summary: This review discusses the reaction mechanisms of glycerol electrooxidation, emphasizing the inferiority of Pd compared to Pt electrodes in cleaving glycerol C-C bonds and the reasons for CO2 generation at high overpotentials. A new reaction mechanism is proposed to explain the generation of side products. Additionally, experimental results for Ni electrodes and the performance of multi-metallic electrocatalysts are presented.
Article
Chemistry, Multidisciplinary
Yu-Fang Tan, Dan Yang, Yu-Hao Yang, Jin-Feng Lv, Lan-Xi Zong, Zhi Guan, Yan-Hong He
Summary: This article describes an electricity-driven radical-polar crossover process for the (homo)cross-1,4-alkoxydimerization of alkenes. A variety of abundant and readily available (hetero)aryl alkenes and (halo)aliphatic alcohols can be used in the reaction to produce 1,4-dialkoxybutane derivatives with moderate to excellent yields. The reaction exhibits broad functional group tolerance and high product diversity. The method is clean and highly atom-economical, with hydrogen gas being the only by-product. Its insensitivity to air makes it efficient and convenient for the construction of various 1,4-dialkoxybutane derivatives.
Article
Chemistry, Organic
Lona Dutta, S. S. Ramasastry
Summary: This study describes a new method for the synthesis of 3HQs under neutral conditions, which also represents the first intramolecular oxyamination of α,β-ynones. The synthetic utility of this method is demonstrated by successfully synthesizing japonine, its analogs, and rare quinoline derivatives.
Article
Chemistry, Physical
Sheng-Mei Lu, Meng-Meng Wang, Xiangfeng Lin, Can Li
Summary: This article reports an efficient iridium catalyst for the hydrogenation of alkyl carboxylic acids to alcohols and esters under mild conditions without any additives. Among the evaluated catalysts, complex 4 shows the highest performance with a TON of 1106 for acetic acid hydrogenation.
Article
Chemistry, Multidisciplinary
Md. Emdadul Hoque, Jin-Quan Yu
Summary: In this study, we report a new method for the gamma-arylation and gamma-lactonization of aliphatic acids, enabled by a L,X-type CarboxPyridone ligand catalyzed Pd(II) reaction. A wide range of gamma-arylated gamma-lactones can be efficiently synthesized in a single step, and the arylated lactones can be further converted into disubstituted tetrahydrofurans, which are prominent scaffolds in bioactive molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Sangeth Jenthra, Totan Mondal, Gregor Kemper, Marcus Lantzius-Beninga, Markus Hoelscher, Walter Leitner
Summary: A highly chemo- and regioselective decarboxylative Heck-type coupling of carboxylic acids and terminal olefins was achieved using a catalytic system composed of Pd(OAc)(2) in the presence of phosphine-sulfonamido ligands. The bulky ligand L1 favored the formation of 1,1-disubstituted branched olefins with high selectivity, while the less bulky ligand L2 resulted in the formation of 1,2-disubstituted linear products in high yield. Detailed mechanistic investigation revealed that the aryl substituent at the sulfonamide group of ligand L1 favored 1,2-insertion, while the less bulky ligand L2 favored 2,1-insertion.
