Article
Chemistry, Multidisciplinary
Qian Xu, Thomas R. Hoye
Summary: This study reports the generation of a relatively rare reactive intermediate called alpha,3-dehydrotoluenes from isolable allenynes. The substructure motif in the allenyne substrates is distinct and complementary to other types of cycloisomerizations. The product profiles obtained under different reaction conditions provide insights into the electronic nature of the produced isomeric DHTs and reveal previously unobserved carbene-like reactivity of the DHT.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Guangjin Zhen, Guohui Zeng, Kai Jiang, Furong Wang, Xiaohui Cao, Biaolin Yin
Summary: This study reports a chemically divergent reaction based on designed indole-tethered (hetero)arylsulfonamides, which involves diradical-mediated ipso-cyclization and controllable cleavage of an inherent C-S bond. The experimental and computational results indicate that the cleavage of the C-S bond in these substrates can be controlled by tuning the heteroaryl moieties. For thiophene, furan, phenanthrene, etc., the radical coupling of double dearomative diradicals (DDDR) precedes over C-S bond cleavage to form cyclobutene fused indolines through double dearomative [2+2]-cycloaddition. For phenyl, naphthyl, pyridyl, indolyl, etc., the cleavage of the C-S bond in DDDR is favored over radical coupling to afford biaryl products.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Applied
Robbie Radjagobalou, Miguel Imbratta, Julie Bergraser, Marion Gaudeau, Gildas Lyvinec, Dominique Delbrayelle, Olivier Jentzer, Jeremy Roudin, Benjamin Laroche, Stephanie Ognier, Michael Tatoulian, Janine Cossy, Pierre-Georges Echeverria
Summary: A selective photochemical monochlorination of 2-fluorotoluene has been developed using a continuous flow process, optimizing key reaction parameters to minimize the formation of dichlorinated by-products. The reaction has been successfully scaled up on a multi decagram scale.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2022)
Article
Chemistry, Organic
Xiaoxuan Li, Haotian Lu, Mingming Ji, Ke Sun, Fangxu Pu, Yun Ding, Aiguo Hu
Summary: In this study, a series of maleimide-based enediynes with macrocyclic lactone moieties were synthesized. These compounds exhibited a low onset temperature and the ability to generate radicals at physiological temperature. Cellular experiments showed that they induced tumor cell apoptosis by cleaving DNA and disrupting the cell cycle distribution.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Organic
Monisha Singha, Prabuddha Bhattacharya, Debashis Ray, Amit Basak
Summary: Nucleophilic addition to p-benzynes derived via Bergman cyclization is a topic of interest, with recent studies showing high regioselectivity achieved through the use of rigid hydrogen atoms to hinder the trajectory of nucleophiles. The products of such reactions are halo naphtho tetrahydroisoquinolines, with steric hindrance by bay hydrogen identified as the main cause of regioselectivity, while electrostatic potential differences and distortions at reactive centers play minor roles in controlling regioselectivity.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Physical
Magnus W. D. Hanson-Heine
Summary: In this study, the properties of cyclophenacene molecules and their isomers were investigated using density functional theory. It was found that cyclophenacenes containing Dewar benzene derivatives have higher energy electronic singlet-triplet state transitions, and the [6]cyclophenacene isomer with two maximally spaced Dewar benzene derivatives has a similar energy to the purely Kekule and PRIME benzenoid isomer. Additionally, the addition of solvent is predicted to stabilize the Kekule and PRIME form.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Biochemistry & Molecular Biology
Natalia A. Danilkina, Ekaterina A. Khmelevskaya, Anna G. Lyapunova, Alexander S. D'yachenko, Alexander S. Bunev, Rovshan E. Gasanov, Maxim A. Gureev, Irina A. Balova
Summary: The scope and limitations of the Nicholas-type cyclization for the synthesis of 10-membered benzothiophene-fused heterocyclic enediynes with different functionalities were investigated. Among the investigated conditions, cyclization via an arenesulfonamide functional group was found to be the most promising, yielding high overall yields. The acylated 4-aminobenzenesulfonamide nucleophilic group was found to be the most convenient for the synthesis of functionalized 10-membered enediynes bearing a clickable function. The synthesized cyclic enediynes exhibited moderate activity against lung carcinoma cells.
Article
Chemistry, Multidisciplinary
Fang Miao, Hanjiao Chen, Sergio Moles Quintero, Guodong Xue, Juan Casado, Yonghao Zheng
Summary: This study presents the synthesis and detailed investigation of an asymmetric N-doped phenalenyl compound (BTAP) for the first time. The synthesized BTAP exhibits a planar configuration and an unexpected zwitterionic ground state with negative charge delocalized around the circumjacent part and positive charge mainly localized on the center.
CHEMICAL COMMUNICATIONS
(2021)
Review
Chemistry, Physical
Eugene B. Caldona, Ernesto I. Borrego, Ketki E. Shelar, Karl M. Mukeba, Dennis W. Smith
Summary: The characteristics of polymers are influenced by the method of polymerization and the structural features of their repeat units. Polymers composed of cyclic repeat units tend to exhibit higher optical transparency, lower water absorption, and higher glass transition temperatures. PFCB and ODA are two ring-forming polymer groups with outstanding thermal stability, chemical resistance, mechanical integrity, and improved processability, offering a wide range of applications.
Editorial Material
Chemistry, Multidisciplinary
Tuhin Patra, Thomas Wirth
Summary: This study investigates a novel oxidative cleavage method for alkenes, which involves the use of photosensitized nitroarenes to produce [3+2] cycloaddition products and convert them into carbonyl compounds. The method offers high site-selectivity and mild oxidation conditions, making it suitable for the synthesis of complex molecular structures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Akihiro Shimizu, Masaaki Hayashida, Yuta Ochi, Daisuke Shiomi, Kazunobu Sato, Takeji Takui, Ryo Shintani
Summary: A zwitterionic open-shell singlet diradical composed of electron-donating anion and electron-accepting cation was synthesized and showed near-infrared absorption. The diradical has a small energy gap between the ground singlet and thermally-excited triplet states (Delta E-ST), which can be changed by solvents.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Mathematics, Applied
Fengwei Li, Qingfang Ye, Hajo Broersma, Ruixuan Ye, Xiaoyan Zhang
Summary: Various VDB topological indices have been introduced in theoretical chemistry, pharmacology, and biology to predict the physio-chemical properties of chemical compounds. This paper focuses on studying the attributes of f-benzenoids, a type of polycyclic aromatic hydrocarbons, by examining extremal values for VDB topological indices with a given order. The extremal f-benzenoids attaining these values are also characterized in this study.
APPLIED MATHEMATICS AND COMPUTATION
(2021)
Article
Chemistry, Multidisciplinary
Henric Steffenfauseweh, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Diego M. Andrada, Rajendra S. Ghadwal
Summary: In this study, the synthesis, characterization, and reactivity of the first cyclic C2As2-diradicaloid compound were reported. The compound exhibits a planar C2As2 ring, is diamagnetic, and shows well resolved NMR signals.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Takumi Nukazawa, Takeaki Iwamoto
Summary: The compound with unsupported bridgehead Si-Si pi bond and ethynyl pi moieties was successfully synthesized, and effective pi conjugation between the unsupported Si-Si pi and ethynyl pi units was observed.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Luis Leyva-Parra, Ricardo Pino-Rios, Diego Inostroza, Miquel Sola, Mercedes Alonso, William Tiznado
Summary: This study investigates the connection between Clar's rule, aromaticity, and magnetic properties of polycyclic benzenoid hydrocarbons using magnetically induced current density analysis. The results reveal the presence of a global ring current in the analyzed polycyclic systems, aligning with Clar's aromatic pi-sextets only in cases involving migrating pi-sextet structures.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Jing Li, Martin J. Lear, Yujiro Hayashi
CHEMICAL COMMUNICATIONS
(2018)
Article
Chemistry, Multidisciplinary
Kei Yamada, Natsuki Shikida, Kazutaka Shimbo, Yuji Ito, Zahra Khedri, Yutaka Matsuda, Brian A. Mendelsohn
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2019)
Article
Biotechnology & Applied Microbiology
Martin J. Lear, Keiichiro Hirai, Kouki Ogawa, Shuji Yamashita, Masahiro Hirama
JOURNAL OF ANTIBIOTICS
(2019)
Article
Chemistry, Medicinal
Kei Yamada, Masakazu Nakazawa, Kayo Matsumoto, Uno Tagami, Takatsugu Hirokawa, Keisuke Homma, Suguru Mori, Ryo Matsumoto, Wakana Saikawa, Seiji Kitajima
ACS MEDICINAL CHEMISTRY LETTERS
(2019)
Review
Biochemistry & Molecular Biology
Kei Yamada, Yuji Ito
Article
Chemistry, Medicinal
Kei Yamada, Ryo Matsumoto, Yumiko Suzuki, Suguru Mori, Seiji Kitajima
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS
(2020)
Article
Chemistry, Applied
Yutaka Matsuda, Kei Yamada, Tatsuya Okuzumi, Brian A. Mendelsohn
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2019)
Article
Chemistry, Multidisciplinary
Jing Li, Martin J. Lear, Yujiro Hayashi
Summary: A new transition metal-free synthesis method for cyclopropanes has been achieved, which tolerates various aryl systems, as well as sulfide or alkene functionality, to yield cis-aryl/cyano cyclopropanes bearing congested tetrasubstituted quaternary carbons.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Subramanian G. Gramani, Ravi K. Sriramula, Karthik Sekar, Eugene G. Yang, Praveena Battu, Aicha Kopecky, Martin J. Lear
Summary: This study presents a concise and (Z)-selective approach to the synthesis of the 14-membered carbocycle of bielschowskysin using naturally occurring chiral starting materials. By employing cyclic diol benzylidene protection, the issues of steric hindrance and alkyne chelation of the ruthenium catalyst in the synthesis process were effectively overcome.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Jing Li, Eunsang Kwon, Martin J. Lear, Yujiro Hayashi
Summary: In halogen chemistry, the reaction between amines and N-halosuccinimides is complex, with NIS mainly forming non-covalent halogen bonded amine complexes and similar behavior observed for NBS, requiring catalysis with an appropriate Brønsted acid.
HELVETICA CHIMICA ACTA
(2021)
Article
Medicine, Research & Experimental
Yutaka Matsuda, Takuya Seki, Kei Yamada, Yuri Ooba, Kazutoshi Takahashi, Tomohiro Fujii, Sayaka Kawaguchi, Takahiro Narita, Akira Nakayama, Yoshiro Kitahara, Brian A. Mendelsohn, Tatsuya Okuzumi
Summary: This study introduces the AJICAP technology for site-specific chemical conjugation of antibodies, resulting in a wide variety of ADCs with stable thiol intermediates. In vivo xenograft studies showed significant tumor inhibition by AJICAP-ADCs, and rat pharmacokinetic analysis indicated an increase in the maximum tolerated dose, expanding the therapeutic index compared to stochastic conjugation technology.
MOLECULAR PHARMACEUTICS
(2021)
Article
Chemistry, Multidisciplinary
Kei Yamada, Arghya Deb, Veronika M. Shoba, Donghyun Lim, Basudeb Maji, Ashley E. Modell, Amit Choudhary
Summary: We report a platform for the rapid development of ionophores using metal-ion chelators. The improved ionophores showed better specificity and performance for Zn-II, as well as superior antibacterial activity and lower toxicity to mammalian cells.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Shoji Kobayashi, Ryo Yamaguchi, Fumiya Yamamoto, Jun Komori, Hotaka Sakamoto, Takahiro Kasashima, Louis Adriaenssens, Martin J. Lear
Summary: An economic and scalable one-pot procedure for converting benzylic or aliphatic alcohols to various N-functionalized amines is reported. The method involves oxidative formation of acid chloride intermediates and the Curtius rearrangement of acyl azides, leading to overall yields of 38-83%. The use of a green solvent and minimal amounts of chlorinating agent contribute to the economic and environmentally friendly nature of the process.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Xiaonan Wang, Silong Xu, Yuhai Tang, Martin J. J. Lear, Wangxiao He, Jing Li
Summary: The replacement of oxoamide units with thioamides is an effective strategy to enhance biological activity and resistance to enzymatic degradation in peptide therapeutics. This study presents a direct coupling method using readily available nitroalkanes and amines with elemental sulfur and base to form thioamides and thiopeptides. The developed method allows for selective and stereo-retentive introduction of thioamide bonds into peptide or protein backbones, enabling the synthesis of diverse thioamides in high yields.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Xin He, Pengchen Ma, Yuhai Tang, Jing Li, Shenyu Shen, Martin J. Lear, K. N. Houk, Silong Xu
Summary: We report a phosphine-catalyzed (3 + 2) annulation of cyclopropenones with various electrophilic pi systems, yielding products including butenolides, butyrolactams, maleimides, and iminomaleimides in high yields with a wide range of substrates. An alpha-ketenyl phosphorous ylide is identified as the key intermediate, which undergoes preferential catalytic cyclization with aldehydes. This phosphine-catalyzed activation of cyclopropenones provides a versatile C-3 synthon for formal cycloadditon reactions.