Article
Chemistry, Multidisciplinary
Austin D. Marchese, Andrew G. Durant, Cian M. Reid, Clara Jans, Ramon Arora, Mark Lautens
Summary: A Pd(0)/blue light catalyzed carboiodination reaction has been reported, which generates a variety of iodinated hetero- and carbocycles. The reaction system is simple and stable, and shows good tolerance towards sensitive functional groups, delivering products in high yields. Experimental evidence supports the reversible C-I bond formation via a single electron mechanism.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Kornkamon Akkarasereenon, Paratchata Batsomboon, Somsak Ruchirawat, Poonsakdi Ploypradith
Summary: ortho-quinone methides can react with arylallenes via a [4+2] cycloaddition reaction to give regioselectively 3-methylene-2-arylchromans. These compounds can be further functionalized to provide the corresponding derivatives.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jiagen Li, Ming Wang, Xuefeng Jiang
Summary: Stereoselective thioglycosylation via palladium-catalyzed allylic rearrangement was successfully achieved in this study, yielding various substituents on alpha-isomer thioglycosides. Additionally, a comprehensive series of aryl and benzyl thioglycosides were obtained through a combination of thiosulfates with glycals derived from different carbohydrates.
Article
Chemistry, Multidisciplinary
Bhawani Shankar, Vinod Khatri, Banty Kumar, Vipin K. Maikhuri, Amit Kumar, Rashmi Tomar, Ashok K. Prasad
Summary: An efficient methodology for synthesizing (2R,3S,4R)-2-hydroxymethyl-3,4-dihydroxy-6-aryl-7-aroylchromanes has been developed, starting from C-glucopyranosyl aldehyde derived from D-glucose. The process involves various chemical reactions to achieve the desired chiral compounds and final product.
Article
Chemistry, Multidisciplinary
Jinshan Li, Wenxue Xi, Saimei Liu, Yaqi Yang, Jianguo Yang, Hanfeng Ding, Zhiming Wang
Summary: This study developed a hexafluoroisopropanol-catalyzed highly diastereoselective formal [4 + 2] cyclization reaction. By employing difluoroenoxysilane as a new C2 synthon, this tandem protocol provides a simple and straightforward approach to assemble multiply functionalized difluorinated chromans with high to excellent diastereoselectivity.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Physical
Shi-Yu Chen, Yu-Hang Song, Shuang Jiao, Chen Zou, Shi-Huan Li, Changle Chen, Xiao-Bing Lu, Ye Liu
Summary: Polyethylenes are widely used synthetic polymers, and introducing functional groups into polyethylene backbone can improve environmental persistence and compatibility with other materials. However, this process is hindered by the formation of alternating polyketones. By reducing the carbonyl density in polyketones, their properties become closer to polyethylene. In this study, Ni and Pd-coordinated cationic catalysts were used for nonalternating carbonylative copolymerization of ethylene, resulting in car-bonyl functionalized polyethylenes with similar properties to commercial high-density polyethylene.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Applied
Jian Xiao, Haonan Zhang, Anyaegbu Chima Ejike, Lu Wang, Minli Tao, Wenqin Zhang
Summary: A series of polyacrylonitrile fibers functionalized with nitrogen-containing ligands were prepared for synthesizing fiber-supported Pd(0) nanoparticle catalysts, with the phenanthroline-functionalized PANF showing the best catalytic activity for the Heck reaction. The PANPhenF-Pd(0) catalyst efficiently stabilized the nanoparticles, characterized by well-dispersed Pd(0) particles of around 3 nm, and could be easily recovered and reused for up to six times with only minimal decrease in catalytic activity and low Pd leaching. The structure of PANPhenF-Pd(0) catalyst was further characterized and a probable mechanism for the Heck reaction catalyzed by the catalyst was proposed.
REACTIVE & FUNCTIONAL POLYMERS
(2021)
Article
Chemistry, Applied
Laiyu An, Linghong Chen, Hongzhou Yang, Ling Ye, Hongjun Yang, Xinying Li, Zhigang Zhao, Xuefeng Li
Summary: A convenient and functionalized vinylogous nucleophile has been used to synthesize bridged bicyclic compounds via cascade Michael/Henry reaction. The reaction showed high reactivity without the need for a catalyst under mild conditions. Various structurally distinctive bicyclo[3.2.1]octanes were obtained in isolated yields of 40-96% with excellent diastereoselectivities (& GE;10:1 dr). The gram-scale synthesis was also demonstrated.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Melek Tercan
Summary: Pd(0) nanoparticles supported on surface functionalized magnetite (Fe3O4/SiO2-NH2/HB@Pd) were used as catalyst for hydrolysis of ammonia borane (AB). The magnetic nanocomposite material was characterized and showed high catalytic activity with 100% yield at 25°C. The effect of catalyst amount and temperature on the reaction rate was also studied.
Article
Chemistry, Organic
Siqi Liu, Wenli Hu, Wenyan Hao, Jianhui Xia, Mingzhong Cai
Summary: In this study, a heterogeneous gold catalyst was developed for the cyclization of (o-alkynyl)phenoxy- or N-(o-alkynylphenyl)tolylsulfonamidoacrylates with alcohols. This catalyst demonstrated comparable activity to the homogeneous counterpart and could be easily recovered and reused multiple times.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Anna N. Philippova, Daria V. Vorobyeva, Pavel S. Gribanov, Fedor M. Dolgushin, Sergey N. Osipov
Summary: An efficient method was developed for accessing highly functionalized proline derivatives by using a Cu(I)-catalyzed reaction. The reaction involved a cascade of [3 + 2]-cycloaddition/ketenimine and a rearrangement/Alder-ene cyclization, resulting in the formation of a new proline framework with high diastereoselectivity.
Article
Chemistry, Organic
Pavel Yu. Ushakov, Sema L. Ioffe, Alexey Yu. Sukhorukov
Summary: In this work, the classical approach to aldol synthesis using isoxazoline was revisited. A [4 + 1] annulation reaction was used to construct the isoxazoline ring bearing an N-oxide moiety to avoid regioselectivity issues. The resulting alpha'-acyloxy-substituted aldols were obtained with good yields and as single diastereomers in most cases. The synthetic use of these aldols was demonstrated by their transformation into diastereomerically pure triols and a structurally related tetrahydrofuran derivative.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Organic
Taotao Chen, Chao Che, Zhefei Guo, Xiu-Qin Dong, Chun-Jiang Wang
Summary: This study developed an asymmetric, catalyst-free inverse electron-demand reaction, successfully synthesizing tetrahydropyridazines containing indole scaffolds with high yield and good enantioselectivity.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Guo-Li Shen, Yuan-Yuan Tan, Yuan Hu, Zhi-Chao Chen, Wei Du, Ying-Chun Chen
Summary: A straightforward approach for the asymmetric synthesis of multifunctionalized β-lactams has been developed, demonstrating advantages of ready substrate availability, broad applicability, high efficiency, and excellent stereoselectivity.
Article
Chemistry, Organic
Qijian Ni, Fangfang Xu, Xiaoxiao Song
Summary: An organocatalytic Michael/aza-Michael cascade reaction was developed for the synthesis of functionalized quinolizine scaffolds with high yields, excellent diastereoselectivity, and E/Z selectivity. This methodology involves the [3 + 3] annulation of 2-pyridylacetates with nitroenynes through dearomative strategy under mild conditions. The versatility of late-stage derivatizations further demonstrates the synthetic utility of this approach.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Ramon Arora, Jose F. Rodriguez, Andrew Whyte, Mark Lautens
Summary: A palladium-catalyzed strategy has been proposed for synthesizing unsymmetrically linked heterocycles within stereoselective tetrasubstituted olefins, with high yields and excellent stereoselectivities achieved using low catalyst loadings. Mechanistic studies suggest a syn-carbopalladation of the carbamoyl chloride followed by Pd-II-catalyzed cyclization of alkyne-tethered nucleophiles.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Rachel J. Baker, Justin Ching, Teh Ren Hou, Ivan Franzoni, Mark Lautens
Summary: The dearomatization of 2-naphthols is a simple method for constructing complex 3D structures from simple planar starting materials using rhodium and acid catalysis under mild conditions. The vinyl cyclopropane molecules formed in this reaction exhibit high chemoselectivity and scalability, and can be further functionalized at different sites. Both computational and experimental evidence were used to understand the reaction mechanism.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Austin D. Marchese, Andrew G. Durant, Mark Lautens
Summary: A simple and modular approach using palladium catalysis to synthesize bis-heterocyclic spirocycles is reported. The method leverages a Mizoroki-Heck-type reaction to generate neopentylpalladium species, allowing for intramolecular C-H activation on a wide array of C-H bonds to produce a variety of spirocycles. The reaction is scalable, allowing for easy incorporation of biologically relevant heterocycles without the need for flash column chromatography.
Editorial Material
Chemistry, Organic
Mark Lautens
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Multidisciplinary
Austin D. Marchese, Bijan Mirabi, Colton E. Johnson, Mark Lautens
Summary: This paper reports a comprehensive study of reversible C-C bond formation using palladium catalysis. It was found that different diastereomers can be converted to the same product under identical catalytic conditions. Experimental and computational studies also investigated key concepts such as the effect of electronic and steric parameters on the C-C bond cleavage step.
Article
Chemistry, Organic
Jonathan Bajohr, Matthias D. Boehme, Jiacheng Gao, F. Ekkehardt Hahn, Mark Lautens
Summary: The diastereoselective synthesis of sulfonylated indolines has been reported. Reactive benzylic sulfinates are generated through a palladium-catalyzed dearomative sulfination of (aza)indole-tethered aryl iodides. These intermediates react with electrophiles in a one-pot, two-step process to give sulfonylated products with good yields and excellent diastereoselectivity. This scalable three-component sequence can also be used for the synthesis of sulfonamides. Furthermore, further derivatizations of aryl iodide containing products lead to the formation of spiro- and alkynylated indoline products.
Article
Chemistry, Physical
Xavier Abel-Snape, Gina Wycich, Mark Lautens
Summary: A palladium-catalyzed three-component domino reaction for accessing indene derivatives is described. The reaction involves the sequential formation of three bonds, with the first two resulting from inter- and intramolecular carbopalladation, and the final bond arising from an attack by a terminating nucleophilic reagent. The starting tether on the iodoarene can be modified to yield either indenes or benzofulvenes. Additionally, the use of an oxabicycle as an acetylene surrogate is demonstrated, and the enantioselective synthesis of indenes is preliminarily explored.
Article
Chemistry, Physical
Mark Lautens, Egor M. Larin, Jeanne Masson-Makdissi, Jin Jang
Summary: In this study, a rhodium-catalyzed domino strategy was developed for the synthesis of oxindole-containing products from simple ortho-bromoaniline-derived acrylamides. Mechanistic and computational studies elucidated that the reaction proceeds through a Heck-type process to generate benzylidene intermediate and subsequent beta-hydride elimination, followed by the formation of RhI-hydride species and a 1,4-conjugate addition to yield the final oxindole products. Importantly, the use of sodium formate was found to be crucial for generating the rhodium hydride species and enabling the catalyst turnover.
Article
Chemistry, Multidisciplinary
E. Ali McKnight, Ramon Arora, Ekadashi Pradhan, Yuriko H. Fujisato, Ayonitemi J. Ajayi, Mark Lautens, Tao Zeng, Christine M. M. Le
Summary: A BF3-catalyzed atom-economical fluorocarbamoylation reaction was reported, which enables the insertion of alkynes into strong C-F bonds through a halide recycling mechanism. The developed method provides stereoselective access to 3-(fluoromethylene) oxindoles and gamma-lactams, including fluorinated derivatives of known protein kinase inhibitors. Experimental and computational studies support a stepwise mechanism for the fluorocarbamoylation reaction involving a cyclization step followed by internal fluoride transfer.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Sean Harrington, Jacob Pyche, Andrew R. Burns, Tina Spalholz, Kaetlyn T. Ryan, Rachel J. Baker, Justin Ching, Lucien Rufener, Mark Lautens, Daniel Kulke, Alexandre Vernudachi, Mostafa Zamanian, Winnie Deuther-Conrad, Peter Brust, Peter J. Roy
Summary: Nematode parasites of humans and livestock are a significant burden to human health, economic development, and food security. The discovery of Nemacol, a novel anthelmintic drug, provides a potential solution to the problem of drug resistance and lack of effective treatments for nematode parasites. Nemacol inhibits the vesicular acetylcholine transporter (VAChT) and enhances the efficacy of existing anthelmintic drugs.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Ramon Arora, Regina M. Oechsner, Clara Jans, Bijan Mirabi, Austin D. Marchese, Mark Lautens
Summary: A palladium-catalyzed epimerization reaction of stereogenic alkyl iodides is reported using an air-stable precatalyst. Mechanistic experiments revealed the stereoinversion of the C-I bond via reversible bond formation, supported by density functional theory studies. Stoichiometric experiments showed that irradiation of isolable alkyl-Pd(II) complexes promoted C-I reductive elimination, with potential application in C-Br bond formation.
Article
Chemistry, Multidisciplinary
Eric N. Donders, Kai V. Slaughter, Christian Dank, Ahil N. Ganesh, Brian K. Shoichet, Mark Lautens, Molly S. Shoichet
Summary: The pK(a) of colloid-forming drugs can be manipulated to achieve endosomal disruption while avoiding phospholipidosis and minimizing toxicity, leading to the design of drug-rich nanoparticles. By synthesizing ionizable derivatives of fulvestrant analogs, which are lipid-stabilized drug colloids, the pK(a) of these ionizable colloids influenced the mechanism of endosomal and lysosomal disruption. This study establishes a tunable and generalizable strategy for endosomal disruption by manipulating the pK(a) of colloid-forming drugs.
Article
Chemistry, Organic
Jonathan Bajohr, Aureilien Dupeux, Daniel Schenk, Clara Jans, Mark Lautens
Summary: The synthesis of bis-heterocyclic spirocycles containing pyrroline and indoline motifs through palladium-catalyzed reactions is reported. In situ generation of palladacycles via Narasaka-Heck/C-H activation reactions using di-tert-butyldiaziridinone as a functionalizing reagent. The scalability of the reaction and the synthetic utility of the spirocyclic products are demonstrated through their deprotection, reduction, and (3 + 2) cycloaddition reactions. Kinetic isotope effect experiments provide evidence for a turnover-limiting C-H functionalization step in the catalytic cycle.
Article
Chemistry, Multidisciplinary
Xavier Abel-Snape, Colton E. Johnson, Bianca Imbriaco, Mark Lautens
Summary: A palladium-catalyzed spirocyclization reaction was reported, which involved the insertion of an oxabicycle into a palladacycle. The reaction proceeded via carbocyclization and a C-H functionalization sequence, and the diastereoselective nature of the insertion was observed. The spirooxindoles produced in the reaction allowed for further transformations and were previously unaccessible.
Article
Chemistry, Organic
Colton E. Johnson, Shangyu Li, Ramon Arora, Bijan Mirabi, Mark Lautens
Summary: This article focuses on the mechanism, recent applications, challenges, and outlook of Ni-catalyzed C-H activation of sp(3)-hybridized carbon atoms. The study highlights the differences between Ni and Pd in C-H activation and discusses the choice of directing groups as well as primary, secondary, and tertiary C-H activation.