Article
Chemistry, Physical
Hajime Maeda, Saki Nakamura, Taniyuki Furuyama, Masahito Segi
Summary: The reaction of 1-naphthyl naphthylmethyl ethers 1 and 2 with Lewis acids in CH2Cl2 resulted in rearrangement of the naphthylmethyl group to different positions of the naphthalene ring. The rearrangement of 2-naphthyl ethers 3 and 4 proceeded to the 1-position. Irradiation of compound 1 in benzene solution led to rearrangement at the 4-position, while rearrangement of compound 2 occurred at the 2- and 4-positions. The regioselectivity of the reactions can be explained by charge density, spin density, steric hindrance, and solvent cage effect.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Chemistry, Applied
Da-Ping Jin, Shi-Qi Cao, Fu Cheng, Ze-Sen Xue, Run-Ze Li, Yan-Lin Pu, Dao-Yong Zhu, Wen Bao, Xue-Tao Xu, Shao-Hua Wang
Summary: An Au(I)-catalyzed cascade reaction involving cyclization and semipinacol rearrangement of 1,6-enynes has been developed for the synthesis of spiro[4.5]decanes and 7-azaspiro[4.5]decanes. The use of JohnPhosAuCl/NaBARF catalyst led to the formation of functionalizable spirocyclic products with high diastereoselectivity ranging from 6.7:1 to > 20:1 dr. A plausible reaction mechanism has been proposed based on previous literature and experimental findings.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Eveline H. H. Tiekink, Pascal Vermeeren, Trevor A. A. Hamlin
Summary: We investigated the uncatalyzed and Lewis acid (LA)-catalyzed cycloaddition reaction between tropone and 1,1-dimethoxyethene using dispersion-corrected relativistic density functional theory (DFT). The LA catalysts BF3, B(C6H5)(3), and B(C6F5)(3) effectively accelerated both [4+2] and [8+2] cycloaddition reactions by lowering the activation barrier by up to 12 kcal mol(-1) compared to the uncatalyzed reaction. Our study revealed that the LA catalyst promoted the cycloaddition reaction pathways through LUMO-lowering catalysis and demonstrated that Pauli-lowering catalysis is not always the operative mechanism in cycloaddition reactions. Selecting the appropriate LA catalyst allowed for regiocontrol of the cycloaddition: B(C6H5)(3) yielded the [8+2] adduct while B(C6F5)(3) produced the [4+2] adduct. The regioselectivity shift was found to be due to the LA's ability to absorb distortion and adopt a trigonal pyramidal geometry around the boron atom.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Organic
Ye Jin, Mao Liu, Hang Cong, Qingmei Ge
Summary: Pinacol rearrangement is an important method for converting 1,2-diols into carbonyl compounds through acid-catalyzed dehydration. It has the ability to install polycyclic skeletons, quaternary carbon centers, and spirocyclic cores, and has applications in the synthesis of natural products and other valuable compounds.
CURRENT ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Liselle Atkin, Hannah J. Ross, Daniel L. Priebbenow
Summary: This study investigates the reactivity of acylsilanes and reveals the participation of light-induced siloxy carbenes in intramolecular reactions. Structural misassignments in previous studies are corrected.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Organic
Shimin Jiang, Haojie Ma, Ruchun Yang, Xian-Rong Song, Qiang Xiao
Summary: Carbo- and heterocycles play crucial roles in drugs, natural products, fine chemicals, and biologically and pharmaceutically active compounds. The development of general, practical, and efficient synthetic approaches to prepare these compounds has attracted significant attention from organic chemists. Cascade cyclization of enynols and diynols has become a powerful tool for constructing various frameworks.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Chenlong Zhu, Thomas R. Hoye
Summary: In this report, a new variant of the HDDA process is revealed, which reduces the activation barrier for the reaction by introducing a central quaternized nitrogen atom. Furthermore, the cyclization of substrates can be achieved spontaneously at room temperature.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Subhash P. P. Chavan, Dinesh B. B. Kalbhor, Rajesh G. G. Gonnade
Summary: A concise and highly diastereoselective bioinspired key cationic cyclization strategy for the asymmetric synthesis of the tricyclic core of (-)-stemoamide has been developed. Precursors of key N-acyliminium ions were obtained from L-tartaric acid and L-malic acid. The use of ethyl acetoacetate derived bifunctional allylidenetriphenylphosphorane reagent in the early stage was advantageous for the rapid construction of highly functionalized pyrrolo[1,2-& alpha;]azepine frameworks.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Debayan Roy, Beeraiah Baire
Summary: A new domino cyclative approach for the synthesis of polycyclic gamma-butenolides from beta-aryl-Z-enoate propargylic alcohols has been developed, showing potential atropisomerism and representing a novel example in organic chemistry. The synthesis process involves constructing both rings synchronously while creating a potential stereogenic rotational axis.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Biochemistry & Molecular Biology
Levente Homolya, David Antal, Mate Nagy, Eva Juhasz-Toth, Marietta Toth, Attila Benyei, Laszlo Somsak, Laszlo Juhasz
Summary: The reactivity of O-peracetylated and O-perbenzoylated 1-COOMe, 1-CONH2 and 1-CN-substituted glycals against O-, S-, N-, and C-nucleophiles in the presence of Lewis acids was investigated. The results showed that the stereoselectivity of the formed products varied with different nucleophiles.
CARBOHYDRATE RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Alexander Kremsmair, Andreas Hess, Benjamin Heinz, Paul Knochel
Summary: Mixed TMP-bases are excellent reagents for the metalation of functionalized aromatics and heterocycles. By combining with Lewis acids, the metalation scope can be increased, and regioselectivity switches can be achieved. Highly reactive lithium bases are also compatible with various Lewis acids, and performing metalations in continuous flow using commercial setups allows for practical and convenient reaction conditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Review
Chemistry, Physical
Maxim V. Musalov, Vladimir A. Potapov, Maria V. Musalova, Svetlana V. Amosova, Leonid B. Krivdin
Summary: Significant progress has been made in the past decade in the development of novel synthetic methods for the preparation of functionalized and condensed compounds using reactions of organic dichalcogenides with acetylenic derivatives. This review focuses on recent developments in the synthesis of organoselenium compounds through reactions of organic diselenides with acetylenes, with a particular emphasis on literature data from the past 5 years. The majority of the discussed material is dedicated to catalytic and electrophile-mediated reactions with aromatic compounds containing a triple bond and nucleophilic functional groups.
Article
Chemistry, Physical
Rohit Kumar Maurya, Swadhapriya Bhukta, Keshav Kishor, Rana Chatterjee, Amarender Goud Burra, Mahender Khatravath, Rambabu Dandela
Summary: Boron-containing organometallic compounds have always intrigued organic chemists due to their wide application in carbon-carbon bond formation reactions. This review focuses on the arylative cyclization reactions using boronic acids as substrates under different transition metals, for the synthesis of densely functionalized heterocycles and bioactive scaffolds. The study highlights the growing interest in the field and provides an overview of recent developments.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Chemistry, Multidisciplinary
Jun-Jie Yin, Yun-Peng Wang, Jun Xue, Feng-Fan Zhou, Xing-Qian Shan, Rong Zhu, Kun Fang, Lei Shi, Shu-Yu Zhang, Si-Hua Hou, Wujiong Xia, Yong-Qiang Tu
Summary: The first total syntheses of polycyclic diterpenes phomopsene (1), methyl phomopsenonate (2), and iso-phomopsene (3) have been achieved through an unusual cascade reorganization of C-C single bonds. This approach involves a synergistic Nazarov cyclization/double ring expansion for rapid and stereospecific construction of the tetraquinane scaffold, as well as a one-pot strategic ring expansion through Beckmann fragmentation/recombination to efficiently assemble the tetracyclic skeleton. The correct structure of iso-phomopsene was determined to be the C7 epimer of the originally assigned structure, and the absolute configurations of the target molecules were confirmed through enantioselective synthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Danila O. Zakharov, Konstantin Chernichenko, Kristina Sorochkina, Shengjun Yang, Ville-Veikko Telkki, Timo Repo, Vladimir V. Zhivonitko
Summary: In this study, we report the nuclear spin hyperpolarization of various alkenes achieved through alkyne hydrogenations with a metal-free hydroborane catalyst. The specific spin dynamics in catalytic intermediates leads to the hyperpolarization of one hydrogen in the alkene, allowing for advanced characterization of the catalytic process.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Xiao-Qing Han, Lei Wang, Ping Yang, Jing-Yuan Liu, Wei-Yan Xu, Chao Zheng, Ren-Xiao Liang, Shu-Li You, Junliang Zhang, Yi-Xia Jia
Summary: A palladium-catalyzed intramolecular enantioselective Mizoroki-Heck reaction of naphthalenes has been developed, leading to the formation of a series of unique heterocyclic compounds with enantiomeric excess values retained. The reaction relies on the use of a chiral sulfonamide phosphine ligand to inhibit competitive and undesired reactions.
Article
Chemistry, Multidisciplinary
Wenjun Luo, Li-Ming Zhang, Zhan-Ming Zhang, Junliang Zhang
Summary: A novel family of PNP ligands (W-Phos) was designed and applied in the copper-catalyzed asymmetric addition of linear Grignard reagents to aryl alkyl ketones. This method allows for the facile synthesis of versatile chiral tertiary alcohols with high yields and excellent enantioselectivities. It also has the potential for the synthesis and modification of various densely functionalized medicinally relevant molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Huanan Wang, Hui Qian, Junliang Zhang, Shengming Ma
Summary: In this study, a palladium-catalyzed enantioselective carbon-phosphorus bond formation reaction affording axially chiral allenyl phosphonates has been developed. The reaction shows high enantioselectivity and good compatibility with a wide range of functional groups.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Juan Feng, Jiayi Shi, Lan Wei, Mingqing Liu, Zhiming Li, Yuanjing Xiao, Junliang Zhang
Summary: In this study, a highly regio- and diastereo-selective palladium/PC-Phos-catalyzed asymmetric Heck/Tsuji-Trost reaction was reported for the synthesis of various functionalized chiral hexahydroindoles with good yields and high enantioselectivity. The application of this reaction to the concise synthesis of (-)-alpha-Lycorane was demonstrated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Wenge Zhang, Pei-Chao Zhang, Yin-Lin Li, Hai-Hong Wu, Junliang Zhang
Summary: This study enables the synthesis of highly selective heterocycles through asymmetric cycloaddition reactions, providing an important method for efficient and selective reactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Yin Yuan, Junfeng Yang, Junliang Zhang
Summary: In this study, a Cu-catalyzed enantioselective decarboxylative cyanation method via the merger of photocatalysis and electrochemistry was reported. This method provides an efficient and straightforward approach for decarboxylative coupling, eliminating the need for stoichiometric chemical oxidants or substrate prefunctionalization. Mechanistic insight on enantioselectivity control was obtained through DFT calculations.
Article
Chemistry, Multidisciplinary
Chun Ma, Yue Sun, Junfeng Yang, Hao Guo, Junliang Zhang
Summary: In this study, an efficient method for the catalytic synthesis of Troger's base analogues with nitrogen stereocenters was reported. The process involved palladium catalysis and the use of home-developed GF-Phos. The method allowed for the rapid construction of a new rigid cleft-like structure with both C and N stereogenic centers, exhibiting excellent efficiency and selectivity. Various applications as a chiral organocatalyst and metallic catalyst precursors were demonstrated, and DFT calculations revealed that NH center dot center dot center dot O hydrogen bonding and weak interaction between the substrate and ligand played crucial roles in achieving excellent enantioselectivity control.
ACS CENTRAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Youshao Tu, Bing Xu, Qian Wang, Honglin Dong, Zhan-Ming Zhang, Junliang Zhang
Summary: In this work, we developed a highly enantioselective Pd/TY-Phos-catalyzed Heck/Tsuji-Trost reaction of o-bromophenols with various 1,3-dienes, allowing expedient access to chiral substituted 2,3-dihydrobenzofurans. This reaction features excellent regio-and enantiocontrol, high functional group tolerance, and easy scalability. More importantly, the demonstration of this method as a highly valuable tool for the construction of optically pure natural products (R)-tremetone and fomannoxin is highlighted.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Shiquan Gao, Chen Wang, Junfeng Yang, Junliang Zhang
Summary: In this study, an enantioselective intramolecular reductive coupling of enynes was achieved via the combination of electrochemistry and cobalt catalysis. The transition-metal catalyzed asymmetric cyclization of 1,6-enynes has been widely used for the construction of carbocycles and heterocycles, but examples under electrochemical conditions are rare. We report a Co-catalyzed enantioselective intramolecular reductive coupling of enynes using H2O as the hydride source, which provides good yields with high regio- and enantioselectivities. This study represents a rare progress on the cobalt-catalyzed enantioselective transformation via electrochemistry with a general substrate scope, and DFT studies suggest the possible reaction pathways.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Li-Ming Zhang, Wenjun Luo, Jiangzhen Fu, Yu Liu, Junliang Zhang
Summary: A newly developed PNP-type W-Phos ligand showed a unique effect on the catalytic asymmetric addition of reactive Grignard reagents to ketimines. This enabled a Cu(I)-catalyzed asymmetric alkylation reaction of N-sulfonyl ketimines, resulting in the formation of optically active α-tertiary amines with high enantioselectivities.
Article
Multidisciplinary Sciences
Jie Han, Siyuan Liu, Huanan Wang, Jie Wang, Hui Qian, Zhiming Li, Shengming Ma, Junliang Zhang
Summary: The 13-H elimination is a crucial step in the carbon-palladium bond quenching for the Heck reaction and has been a challenge to control enantioselectivity. Here, we developed a concise and efficient method to construct chiral allenes from fully substituted enol triflates through enantioselective 13-H elimination of alkenyl palladium species under mild conditions. The identified Xu-Phos catalysts play a crucial role in chemoselectivity and enantioselectivity. Multiple linear regression analysis shows the significance of steric effect on enantioselectivity. DFT calculations propose an intramolecular base-assisted deprotonation mechanism for this progress, and energy decomposition analysis suggests that the difference in electrostatic energy of the transition states dominates the stereoselectivity.
Review
Chemistry, Multidisciplinary
Bing Xu, Quanpu Wang, Chao Fang, Zhan-Ming Zhang, Junliang Zhang
Summary: This review summarizes the latest advancements in enantioselective palladium-catalyzed cyclization reactions over the past eleven years. The review is organized into thirteen sections based on the different types of transformations involved. Chiral palladium catalysts have shown outstanding features in promoting a plethora of enantioselective cyclization reactions, providing convenient access to structurally diverse chiral carbo- and hetero-cycles.
CHEMICAL SOCIETY REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Zhi-Mao Zhang, Junliang Zhang, Quan Cai
Summary: In this study, seven pentacyclic 19-nor-clerodane diterpenoids were collectively synthesized using an asymmetric reaction. A key feature of the synthesis was the generation of a versatile intermediate through late-stage oxidation state adjustments. This study provides a concise and efficient synthetic route for these compounds.
Article
Chemistry, Multidisciplinary
Huanan Wang, Hui Qian, Junliang Zhang, Shengming Ma
Summary: A new reaction method for the synthesis of axially chiral allenyl phosphonates through palladium-catalyzed carbon-phosphorus bond formation has been developed. The reaction exhibits high yields and enantioselectivity, and can accommodate a wide range of functional groups. Mechanistic studies have revealed an important kinetic resolution process.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Yue Sun, Chun Ma, Zhiming Li, Junliang Zhang
Summary: This article reports an efficient method for the synthesis of chiral pyrrolidines and piperidines through a palladium-catalyzed carbenylative amination reaction of N-tosylhydrazones and (E)-vinyl iodides. The reaction shows high selectivity and good yields, and can be easily scaled up. It also enables the efficient synthesis of a natural product (-)-norruspoline.
