Article
Chemistry, Multidisciplinary
Kanji Niwa, Masao Ohashi, Kaili Xie, Chen-Yu Chiang, Cooper S. Jamieson, Michio Sato, Kenji Watanabe, Fang Liu, K. N. Houk, Yi Tang
Summary: We have discovered biosynthetic pathways that can produce and transform conjugated octaenes and nonaenes into complex natural products. The biosynthesis of (-)-PF1018 involves an enzyme called PfB, which controls the regio-, stereo-, and periselectivity of multiple reactions starting from a conjugated octaene. By using PfB as a starting point, we found a homologous enzyme, BruB, that facilitates diene isomerization, tandem 8π-6π-electrocyclization, and a 1,2-divinylcyclobutane Cope rearrangement to generate a novel compound not previously found in nature.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Julian M. Feilner, Immanuel Plangger, Klaus Wurst, Thomas Magauer
Summary: This study utilized highly functionalized bifunctional alkenes to achieve a polyene tetracyclization, leading to the total synthesis of the tricyclic diterpenoid pimara-15-en-3 alpha-8 alpha-diol. The versatile route also allowed for the preparation of a diverse library of cyclization precursors for the total synthesis of the tetracyclic nor-diterpenoid norflickinflimiod C, providing insights into complex pentacyclic products.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Rustam B. Shnigirev, Igor A. Ushakov, Valentin A. Semenov, Alexander Yu. Rulev
Summary: This article describes the reactions of alpha-chalcogen, alpha-halo, or alpha-amino substituted enals with terminal alkynes, leading to propargyl alcohols (for O-, S-, Cl-, and Br-bearing substrates) or unexpected 2-amino-2-cyclopentenones (for aminoenals). The key feature of these reactions is the rearrangement of adducts with amino groups on silica gel, triggering further cyclization to five-membered carbocycles.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Crystallography
Weiqing She, Zhenzhen Xu, Lianjie Zhai, Junlin Zhang, Jie Huang, Weiqiang Pang, Bozhou Wang
Summary: Due to the introduction of oxygen atoms, N-oxide energetic compounds possess unique advantages in terms of oxygen balance, detonation properties, and energy density, which have attracted extensive attention from researchers worldwide. This article provides a comprehensive review of the synthetic strategies for two categories of N-oxides, azine N-oxides and azole N-oxides, and discusses the reaction mechanisms of aromatic N-oxide frameworks and their applications in creating high-energy substances. Furthermore, the energetic properties of N-oxide energetic compounds are compared and summarized.
Article
Chemistry, Organic
Yongliang Tu, Peng Shi, Carsten Bolm
Summary: A photochemical method for synthesizing alpha-keto-N-acyl sulfoximines from NH sulfoximines and gem-difluoroalkenes has been developed. The reaction proceeds in air without the need for a photocatalyst or additional oxidant, with mechanistic studies indicating that the two oxygen atoms in the products come from water and dioxygen.
Article
Chemistry, Multidisciplinary
Mithun Chakraborty, Gaddam Mahesh, Omkar R. Nakel, Gautamee Chavda, Susarla Anusha, Gangarajula Sudhakar
Summary: A novel method has been developed for the preparation of highly substituted functionalized indenes through a two-step reaction, resulting in good to excellent yields.
Article
Chemistry, Organic
Alexander A. Golovanov, Ivan S. Odin, Dmitry M. Gusev, Anna V. Vologzhanina, Ilya M. Sosnin, Stanislav A. Grabovskiy
Summary: The regioselective synthesis of pyrazole derivatives was achieved by cyclocondensation of cross-conjugated enynones with arylhydrazines, utilizing low-cost starting compounds. The electronic effect of the substituent in enynone determined the reaction path, leading to either pyrazoles or 4,5-dihydro-1H-pyrazoles. The obtained pyrazoles exhibit fluorescent properties with a high quantum yield of up to 31%.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Jackson J. Hernandez, Alison J. Frontier
Summary: We report a Bronsted acid-catalyzed carbocyclization cascade that enables the synthesis of fused heterotricycles. The method exhibits high diastereoselectivity and produces versatile scaffolds with various functional groups for further derivatization.
Review
Chemistry, Multidisciplinary
Jenna L. Miller, Jean-Marc I. A. Lawrence, Freddy O. Rodriguez del Rey, Paul E. Floreancig
Summary: This review primarily focuses on the application of carbon-hydrogen bond functionalizations in organic synthesis, with a particular emphasis on the mechanism, reaction development, natural product synthesis applications, approaches to catalysis, and use in enantioselective processes for hydride abstractions by quinone, oxoammonium ion, and carbocation oxidants. In addition to the commonly used quinone, oxoammonium ion, and carbocation hydride-abstracting agents, the potential of weaker ketone and triaryl borane oxidants has also been studied.
CHEMICAL SOCIETY REVIEWS
(2022)
Review
Biochemistry & Molecular Biology
Sasadhar Majhi
Summary: Natural products and their analogues are essential in drug discovery and development, with total synthesis of secondary metabolites aiding in determining the complex structures of molecules of natural origin. Norrish type I and II reactions are crucial steps in the total synthesis of natural products, playing important roles in organic synthetic chemistry.
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
(2021)
Article
Chemistry, Organic
Hongchen Li, Lidong Shan, Lin Min, Yunxiang Weng, Xinyan Wang, Yuefei Hu
Summary: A novel tandem synthesis of 1,3-disubstituted naphthalenes is developed using TfOH-promoted directed-aldol and Friedel-Crafts reactions. The discovery of a chemoselective directed-aldol reaction between different ketones with alpha-hydrogens enables the efficient creation of new C-C bonds and a benzene ring in one pot.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Masanari Hirahara, Yasushi Umemura
Summary: Photosubstitution reactions of cis-[Ru(bpy)(2)(MeCN)(2)](2+) with a pyrazole ligand were studied, revealing that the presence of a mild base enhanced a second photosubstitution reaction. The yields of the reaction were further increased in solvents with moderate coordinating properties.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Keisuke Nishikawa, Toshiki Niwa, Kento Nishikibe, Momochika Kumagai, Yoshiki Morimoto
Summary: This study focused on the chemical synthesis of feroniellin analogs isolated from Feroniella lucida, establishing a novel ring-size-divergent synthetic strategy for monoterpenic five- to seven-membered ethereal rings. The short and comprehensive synthesis of feroniellins was achieved in only two steps, leading to the revision of proposed structures and determination of absolute configurations, along with investigation of their preliminary anti-inflammatory activities.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Mingshi Pan, Xiabin Wang, Yixin Tong, Xiaodong Qiu, Xiaobao Zeng, Biao Xiong
Summary: A new strategy for the direct synthesis of functionalized pyrroles from beta-amino alcohols and ynones has been demonstrated. This method proceeds in an atom- and step-economic fashion and offers the advantages of broad substrate scope, operational simplicity, and water and hydrogen gas as the sole by-products, providing an alternative and sustainable path to access functionalized pyrroles.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Yan Hu, Jiang Nan, Jiacheng Yin, Guanjie Huang, Xin Ren, Yangmin Ma
Summary: A novel Rh-catalyzed C-H/C-H alkenylation of N-arylmethanimines with vinylene carbonate has been reported, giving access to C3,C4-nonsubstituted quinolines. This process is simple, requires lower catalyst loading, and allows for postfunctionalization with bioactive molecules.
Review
Chemistry, Multidisciplinary
Dongsheng Xue, Haibing He, Shuanhu Gao
Summary: This review highlights strategies for building the tetracyclic ring skeleton and the all-carbon quaternary center for total syntheses of wortmannin and viridin, which are furanosteroids with potential pharmaceutical applications.
Article
Chemistry, Organic
Chaoying Zheng, Tao Xie, Haibing He, Shuanhu Gao
Summary: A new approach was developed for the asymmetric total synthesis of (+)-PD-116740, involving a sequence of asymmetric dihydroxylation followed by oxidative cyclization. A new Cu salt was found to be the best oxidant for inducing the oxidative coupling and phenol oxidation, providing a valuable strategy for future pharmaceutical research.
Article
Chemistry, Organic
Kuanwei Chen, Tao Xie, Yanfang Shen, Haibing He, Xiaoli Zhao, Shuanhu Gao
Summary: The study describes the first asymmetric total synthesis and structural determination of calixanthomycin A, using a concise modular strategy to assemble the hexacyclic skeleton and stereoselective glycosylation. This approach enabled the determination and assignment of the absolute configuration of C-25 and the monosaccharide derivative of L-glucose.
Article
Chemistry, Multidisciplinary
Mengmeng Xu, Min Hou, Haibing He, Shuanhu Gao
Summary: This study developed a new synthetic method for constructing aryltetralin lactone lignans and successfully synthesized several natural lignans using this methodology. The synthesized aglacins and small-molecule library created new opportunities for SAR studies of the podophyllotoxin family of natural products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Zhengyuan Xin, Hui Wang, Haibing He, Xiaoli Zhao, Shuanhu Gao
Summary: The asymmetric total synthesis of norzoanthamine was achieved using radical reactions as key steps. This approach allowed for precise control of stereochemistry and construction of the highly congested heptacyclic skeleton, addressing a major synthetic challenge in most zoanthamine alkaloids.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Baochao Yang, Guoen Wen, Quan Zhang, Min Hou, Haibing He, Shuanhu Gao
Summary: Perovskones and hydrangenones are a family of structurally complex triterpenoids mainly isolated from Salvia medicinal plants, showing a wide range of biological activities such as antitumor and antiplasmodial activities. The total synthesis of these compounds involved asymmetric photoenolization/Diels-Alder reactions, bioinspired Diels-Alder reactions, and late-stage oxidations and ring forming steps. Studies suggest that perovskatone D may be a precursor for the biosynthesis of perovskones, while the formation of hydrangenone and hydrangenone B may involve an oxidative ring cleavage and ring regeneration process.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Dongsheng Xue, Yonglei Que, Hao Shao, Haibing He, Xiaoli Zhao, Shuanhu Gao
Summary: The study on excited-state Nazarov reactions of dicyclicvinyl ketones showed their potential in synthesizing complex natural products, by constructing core tricyclic compounds with specific stereochemistry.
Article
Chemistry, Organic
Zhengyuan Xin, Hui Wang, Haibing He, Shuanhu Gao
Summary: This paper focuses on the importance of contiguous all-carbon quaternary centers in natural products and recent synthetic strategies used in total syntheses. By reviewing 12 representative synthetic examples, the power of these reactions in constructing such centers is showcased to inspire future exploration.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Shaolei Ding, Yingbo Shi, Baochao Yang, Min Hou, Haibing He, Shuanhu Gao
Summary: We describe the asymmetric total synthesis of periglaucines A-C, N,O-dimethyloxostephine and oxostephabenine. Key strategies include a regio- and diastereoselective Hayashi-Miyaura reaction, an intramolecular photoenolization/Diels-Alder reaction, and a bio-inspired intramolecular Michael addition and transannular acetalization.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Hui Wang, Yi Liu, Hongyuan Zhang, Baochao Yang, Haibing He, Shuanhu Gao
Summary: The asymmetric total syntheses of cephalotaxus C19 diterpenoids, which possess a unique cycloheptene A ring with a chiralmethyl group at C-12, were achieved using a universal strategy. Six members, including previously unreported compounds, were successfully synthesized. The concise approach involved a Nicholas/Hosomi-Sakurai cascade reaction to generate the cycloheptene ring with a chiral methyl group, followed by an intramolecular Pauson-Khand reaction for the construction of the target molecules' complete skeleton. This work provides a new strategy for the synthetic analysis of cephalotaxus diterpenoids and structurally related natural products.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Xiao-Long Lu, Yuanyou Qiu, Baochao Yang, Haibing He, Shuanhu Gao
Summary: The asymmetric total synthesis of (+)-xestoquinone and (+)-adociaquinones A and B was achieved in 6-7 steps using an easily accessible meso-cyclohexadienone derivative. The strategy provides a scalable route to prepare target molecules and their derivatives for further biological studies.
Article
Chemistry, Multidisciplinary
Min Hou, Mengmeng Xu, Baochao Yang, Haibing He, Shuanhu Gao
Summary: All-carbon quaternary stereocenters are common in natural products and drugs, but are challenging to construct due to their crowded chemical environment. A chiral titanium promoted enantioselective PEDA reaction has been developed to synthesize molecules with vicinal all-carbon quaternary centers, potentially facilitating the total synthesis of complex natural products or drug-like molecules.
Article
Chemistry, Organic
Xiao-Long Lu, Baochao Yang, Haibing He, Shuanhu Gao
Summary: An efficient approach to naphthol and naphthalene scaffolds has been developed using a sequence involving tandem Ti(Oi-Pr)(4)-promoted photoenolization Diels-Alder (PEDA) and aromatization reactions. This strategy was successfully utilized to synthesize the core skeletons of the bioactive marine natural products garveatin C and exiguaquinol.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Hongyuan Zhang, Haibing He, Shuanhu Gao
Summary: The asymmetric synthesis of the complex C-18 Cephalotaxus dinorditerpenoid cephanolide B was achieved for the first time using a remote hydroxyl group directed hydrogenation strategy and a sequence of modified transformations. The key hexahydrofluorenone core skeleton and selective reductions were crucial in achieving the target compound.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Delu Jiang, Kunyun Xin, Baochao Yang, Yanyu Chen, Quan Zhang, Haibing He, Shuanhu Gao