Article
Chemistry, Organic
Sebastian Fischer, Terrence-Thang H. Nguyen, Andreas Ratzenboeck, Huw M. L. Davies, Oliver Reiser
Summary: A stereoselective, solvent- and metal-free method for endocyclic C-C bond cleavage of monocyclopropanated cyclopentadienes mediated by strong acids has been developed. It leads to the formation of highly functionalized six-membered carbocycles with high stereocontrol. The critical step involves the formation of a cyclopropyl carbocation that undergoes endocyclic ring opening through an SN2'-type attack of various nucleophiles. Subsequent synthetic transformations demonstrate the versatility of the resulting cyclohexenes for the synthesis of compounds with nonconventional substitution patterns.
Article
Chemistry, Organic
Victoria Sinka, Israel Fernandez, Juan I. Padron
Summary: A new methodology for the synthesis of tetrahydroazepines has been developed, utilizing the aza-Prins cyclization in combination with the Peterson-type elimination reaction. This single-step reaction allows for the formation of a C-N, C-C bond, and an endocyclic double bond, and can be performed under mild reaction conditions using iron(III) salts as sustainable catalysts. DFT calculations provide support for the proposed mechanism.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Hao Li, Fan Wu, Yang Pan, Yuting Zhang, Roser Pleixats, Jianming Pan
Summary: With the rapid development of the automobile industry and increasingly strict regulations on automobile exhaust emissions, the demand for palladium will increase as the production of waste purification catalysts for automobile exhaust increases. Recycling waste three-way catalysts is an important way to obtain palladium resources, but obtaining highly selective adsorbents for palladium is still a challenge. In this study, two different Pd2+ selective composite adsorbents were successfully fabricated and characterized. The experimental results showed that both adsorbents exhibited high selectivity towards Pd2+ and remained stable during cyclic adsorption-desorption runs.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Chemistry, Multidisciplinary
Jiawang Liu, Carolin Schneider, Ji Yang, Zhihong Wei, Haijun Jiao, Robert Franke, Ralf Jackstell, Matthias Beller
Summary: This study describes a new method for chemo-, regio-, and stereoselective mono-hydroamidation of (un)symmetrical 1,3-diynes, utilizing an advanced palladium catalyst system with the ligand Neolephos. The success of this novel transformation is demonstrated by the diversification of several structurally complex molecules and marketed drugs, highlighting the synthetic value of the approach for synthesizing useful α-alkynyl-α, β-unsaturated amides. Control experiments and density-functional theory computations indicate the crucial role of the substrate in controlling the regioselectivity of unsymmetrical 1,3-diynes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Karthick Govindan, Wei-Yu Lin
Summary: A LiOH-promoted hydrolysis selective C-N cleavage method for the synthesis of primary amides under mild conditions has been developed. The reaction shows high selectivity and yield for various aryl and alkyl substituents, and can be applied for gram-scale synthesis using a continuous flow method. This new methodology is applicable for both batch and flow conditions in synthetic and industrial applications.
Article
Chemistry, Multidisciplinary
Shuai Liu, Pengchen Ma, Lu Zhang, Shenyu Shen, Hong-Jie Miao, Le Liu, K. N. Houk, Xin-Hua Duan, Li-Na Guo
Summary: An efficient alkoxyl radical-triggered ring expansion/cross-coupling cascade was developed under cheap metal catalysis. A wide range of medium-sized lactones and macrolactones were constructed in moderate to good yields, along with diverse functional groups. The proposed catalytic cycle for this tandem reaction involves Cu(i)/Cu(ii)/Cu(iii).
Article
Chemistry, Organic
Yin-Jun Chen, Hui-Bei Xu, Hao Liu, Lin Dong
Summary: A convenient and atom-economical rhodium(iii)-catalyzed hydroacylation reaction has been developed for the synthesis of spirobenzofuranones and diketones. The use of ortho-hydroxyl-group-assisted aldehyde C-H cascade [4 + 1] annulation enhances the efficiency of spiro compound formation.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Physical
Liangpang Xu, Po Keung Wong, Zhifeng Jiang, Jimmy C. Yu
Summary: This article describes an innovative application of iodide-based photocatalytic process for the efficient degradation of phenolic pollutants, even in complex water matrixes.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Organic
Liu-Liang Mao, An-Xi Zhou, Xian-Hong Zhu, Huanan Peng, Li-Xia Quan, Jie-Ping Wan, Shang-Dong Yang
Summary: We have developed an efficient and facile visible-light-mediated tandem difluoromethylation/cyclization of alkenyl aldehydes using easily accessible and air-stable [Ph3PCF2H]Br-+(-) as the difluoromethylation reagent. Various CF2H-substituted chroman-4-one skeletons and their derivatives are efficiently produced in moderate to good yields with excellent chemoselectivity under mild reaction conditions.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Vladyslav Smyrnov, Jerome Waser
Summary: An electrophile-induced semipinacol rearrangement of cyclopropenylcarbinols is described, enabling the synthesis of polyfunctionalized cyclopropanes under mild metal-free conditions. The reaction demonstrates broad scope, accommodating various electrophiles, migrating groups, and substitution patterns on the cyclopropene. It is particularly useful for the synthesis of small ring-containing spirocycles, which are important building blocks in medicinal chemistry.
Article
Chemistry, Multidisciplinary
Liping Guo, Yuancheng Liu, Haiou Zeng, Shengping Zhang, Ruiyang Song, Jing Yang, Xiao Han, Ying Wang, Luda Wang
Summary: This study successfully fabricates functionalized graphene nanopores through the decoupling etching and in situ covalent modification, achieving precise regulation of ion transport behaviors. The functionalized graphene nanopores exhibit asymmetric ion transport behaviors and efficient ion sieving, and also show potential applications in energy conversion.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Chuxiong Peng, Fengyan Gu, Xiaofeng Lin, Ning Ding, Qichen Zhan, Peng Cao, Tao Cao
Summary: By reacting readily available cyclopropenes with sulfonyl iodides in water, beta-iodo cyclopropyl sulfones were selectively formed, which are important 3C starting materials with privileged structures in medicinal chemistry. This method is operationally convenient and environmentally friendly with water as the sole solvent, avoiding transition metals and air-sensitive reagents, and chromatography-free purification. It can be extended to various styrenes and alkynes, with excellent anti-addition selectivity in reactions with alkynes. Additionally, it has been successfully applied in the post-modification of natural products and drugs, as well as the synthesis of quinolinone MAT2A inhibitor and dipeptide renin inhibitor.
Article
Chemistry, Physical
Haitao Liu, Feng Chen, Nannan Zhao, Sai V. C. Vummaleti, Michael B. Sullivan, Jackie Y. Ying, Lei Wang
Summary: Ring expansion reactions are efficient tools in synthetic and medicinal chemistry, but the strategy involving sulfur ylide-initiated [1,4]-sigmatropic rearrangement is still underexploited. In this study, a rhodium-catalyzed ring expansion of thiochromenes and aromatic thiophenes was disclosed, enabling the straightforward assembly of polyaromatic oxathionines and oxathiocines with diverse functionalities.
Article
Chemistry, Physical
Haitao Liu, Feng Chen, Nannan Zhao, Sai V. C. Vummaleti, Michael B. Sullivan, Jackie Y. Ying, Lei Wang
Summary: A rhodium-catalyzed ring expansion reaction has been discovered for the synthesis of polyaromatic oxathionines and oxathiocines with diverse functionalities.
Article
Materials Science, Multidisciplinary
Xiang Deng, Fengzhu Li, Quan Wang, Danjun Liu, Francis Lin, Dong Shen, Dangyuan Lei, Yung-Kang Peng, Zonglong Zhu, Alex K. -Y. Jen
Summary: Interface engineering using robust fluoroterminated TiO2 nanosheets (F-TiO2 NSs) as interlayers between perovskite and electron-transporting layers greatly enhances the performance and stability of inverted perovskite solar cells. The flat morphology of F-TiO2 NSs allows for close contact with perovskite and abundant surface fluoro groups to interact with ions, preventing the formation of cation vacancies and alleviating surface defects, leading to a remarkable power conversion efficiency of 22.86%. Devices with F-TiO2 NSs interlayers also exhibit enhanced operational stability, maintaining over 90% of their initial efficiencies after 1,000 hours of monitoring at the maximum power point under day/night cycles.
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)
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
Abdoul G. Diallo, Deborah Paris, Djiby Faye, Sylvain Gaillard, Mark Lautens, Jean-Luc Renaud
Summary: This study reports a general approach for the allylation of oxa- and azabenzonorbornadienes by merging organophotoredox and nickel catalysis. The method allows for selective allylation of various heterocyclic alkene derivatives with a broader range of allylic acetate compounds. Notably, the reaction does not require air-sensitive organometallic species or metal reductants.
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, 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.