Article
Chemistry, Multidisciplinary
Kristine Klimovica, Julius X. Heidlas, Irvin Romero, Thanh V. Le, Olafs Daugulis
Summary: This article reports sandwich diimine-copper(I) catalysts for C(sp(3))-H bond functionalization, demonstrating rare examples of base-metal catalyzed, intermolecular C(sp(3))-H functionalizations using unactivated diazo compounds. The electrophilicity and unique steric environment of the sandwich-copper catalysts are likely reasons for their catalytic efficiency.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Aoife M. Buckley, Daniel C. Crowley, Thomas A. Brouder, Alan Ford, U. B. Rao Khandavilli, Simon E. Lawrence, Anita R. Maguire
Summary: A new class of dirhodium carboxylate catalysts, derived from specific 2-fenchyloxy or 2-menthyloxy arylacetic acids, have shown excellent enantioselectivity and trans diastereoselectivity across a range of transformations. These catalysts are highly efficient in various reactions, such as C-H insertion, intramolecular aromatic addition, and oxonium ylide formation and rearrangement, displaying up to 93% ee in product yield.
Article
Chemistry, Multidisciplinary
Thanh V. V. Le, Irvin Romero, Olafs Daugulis
Summary: In this study, trifluoroethylation and pentafluoropropylation reactions of unactivated C(sp(3))-H bonds in alkyl esters, halides, and protected amines were catalyzed by sandwich-diimine copper complex. The reactions took place in dichloromethane solvent at room temperature. Compounds with stronger electron-withdrawing substituents showed higher selectivities for C-H insertions. Preliminary mechanistic studies suggested that the reaction mechanism involves the formation of a pre-equilibrium sandwich-diimine copper-CF3CHN2 complex, followed by rate-determining loss of nitrogen to generate the reactive copper carbene. The carbene reacted with trifluoromethyldiazomethane much faster than with 1-fluoroadamantane, explaining the need for slow addition of the diazo compound.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Joomyung Jun, Ronald T. Raines
Summary: The synthesis of alpha-aryl-alpha-diazoamides was achieved through a two-step process involving Pd-catalyzed C-H arylation and aminolysis, enabling the esterification of carboxyl groups in aqueous solution to become substrates for an esterase. This broad synthetic route paves the way for further development of diazo compounds in chemical biology.
Article
Chemistry, Multidisciplinary
Vaishnavi N. Nair, Volga Kojasoy, Croix J. Laconsay, Wang Yeuk Kong, Dean J. Tantillo, Uttam K. Tambar
Summary: The study developed catalyst-controlled regiodivergent rearrangements of onium-ylides derived from indole substrates, with experimental and computational studies revealing different mechanistic pathways. The methodology was successfully applied in the total synthesis of the natural product and further functional group transformations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Rui-jun Peng, Yuan Chen, Xue-jing Zhang, Ming Yan
Summary: A Rh(iii)-catalyzed ortho C-H migratory insertion of N-nitrosoanilines with naphthoquinone carbenes has been developed, yielding the desired products in good yields under mild reaction conditions. Diverse elaborations of the products were also explored, making this method valuable for the synthesis of biarylamines and their derivatives.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Qing Sun, Yuzhu Peng, Yujing Wang, Xiaoguang Bao
Summary: Here, a photoredox-catalyzed insertion reaction of sulfoxonium ylides with carboxylic acids is reported, providing a practical method for the preparation of a-acyloxy ketones with a wide range of carboxylic acids under mild and simple conditions. Experimental and computational studies suggest a stepwise proton-assisted electron transfer mechanism for this reaction.
Article
Chemistry, Organic
Julia O. Strelnikova, Nikolai Rostovskii, Olesya Khoroshilova, Alexander F. Khlebnikov, Mikhail S. Novikov
Summary: A high-yielding method for synthesizing 2H-1,3,5-oxadiazines by the rhodium(II)- or copper(II)-catalyzed reaction of 1,2,4-oxadiazoles with alpha-diazo esters has been developed, where the N2-attack and N4-attack of the carbenoid cause different oxadiazole ring openings controlled by the substitution at C5.
SYNTHESIS-STUTTGART
(2021)
Article
Multidisciplinary Sciences
Zhaohong Liu, Yong Yang, Qingmin Song, Linxuan Li, Giuseppe Zanoni, Shaopeng Liu, Meng Xiang, Edward A. Anderson, Xihe Bi
Summary: This study reports a chemoselective N-H insertion reaction of inexpensive aqueous ammonia using a TpBr3Ag-catalyzed two-phase system, leading to the conversion into value-added primary amines. The reaction exhibits high chemoselectivity and allows the coupling of inorganic nitrogen sources with diazo compounds or N-triftosylhydrazones to produce useful primary amines.
NATURE COMMUNICATIONS
(2022)
Review
Chemistry, Organic
Vaishnavi N. Nair, Uttam K. Tambar
Summary: Onium ylides are reactive intermediates that are important in various chemical transformations. Metal-catalyzed onium ylide rearrangements have been developed as efficient methods for forming C-C bonds and new stereogenic centers. Selective catalytic onium ylide rearrangements have been achieved in allylic and propargylic systems, but are more challenging in aromatic systems.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Wengang Guo, Ying Zhou, Hongling Xie, Xin Yue, Feng Jiang, Hai Huang, Zhengyu Han, Jianwei Sun
Summary: In this study, the first metal-free asymmetric H-X bond insertion of its kind was achieved by utilizing visible light as a promoter and a chiral phosphoric acid as a catalyst. Under mild conditions, alpha-diazoesters and aryl amines smoothly underwent N-H bond insertion to form enantioenriched alpha-aminoesters with high efficiency and good enantioselectivity. The key to success was the use of DMSO as an additive, which facilitated the rapid capture of the highly reactive free carbene intermediate to form a domesticated sulfoxonium ylide.
Article
Chemistry, Multidisciplinary
Bastiaan Kooij, Paul Varava, Farzaneh Fadaei-Tirani, Rosario Scopelliti, Dimitrios A. Pantazis, Gerard P. Van Trieste, David C. Powers, Kay Severin
Summary: In this study, we report the structural characterization of copper complexes with both bridging and terminal alkenylidene ligands. The complexes were obtained by irradiation of Cu-I complexes with N-heterocyclic diazoolefin ligands. The isolation and structural characterization of the complex with a terminal alkenylidene ligand were achieved through crystalline matrix isolation and in crystallo photolysis at low temperature.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Pinki Sihag, Trisha Chakraborty, Masilamani Jeganmohan
Summary: A redox-neutral mild methodology for allylic C-H alkylation of unactivated alkenes with diazo compounds is demonstrated. The protocol avoids the undesired cyclopropanation of alkenes and is compatible with various functional groups. A rhodacycle pi-allyl intermediate is synthesized and proven to be the active intermediate, with additional mechanistic investigation aiding in elucidating the possible reaction mechanism.
Article
Chemistry, Multidisciplinary
Jia-Yi Shou, Xiu-Hua Xu, Feng-Ling Qing
Summary: Pentafluorosulfanyl chloride (SF5Cl) is commonly used in organic synthesis, but its preparation often involves hazardous reagents and specialized equipment. Researchers have developed a safe and practical method to prepare a stable and easy-to-handle solution of SF5Cl without the need for gas-phase reagents, demonstrating its potential through synthetic applications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Nicholas J. Porter, Emma Danelius, Tamir Gonen, Frances H. Arnold
Summary: This study developed a catalyst that uses diazirines as carbene precursors, providing a new strategy for selective carbene transfer. By engineering variants of ApePgb protoglobin, selective carbene transfer from diazirines can be achieved at room temperature. The structure of an ApePgb variant, determined by microcrystal electron diffraction, revealed how evolution has enhanced access to the heme active site for this new-to-nature catalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Tsubasa Ito, Shingo Harada, Haruka Homma, Hiroki Takenaka, Shumpei Hirose, Tetsuhiro Nemoto
Summary: This study developed a new method for achieving highly enantioselective dearomatization of chemically inert arenes, leading to the synthesis of polycycles with multiple stereogenic centers. Mechanistic investigations revealed the origin of chemo- and enantioselectivity in the reaction process.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Applied
Mai Yanagawa, Shingo Harada, Shumpei Hirose, Tetsuhiro Nemoto
Summary: The study developed a rhodium-catalyzed C-H functionalization reaction for synthesizing 2,3-fused indole variants using an alpha,beta-unsaturated enone as a directing group and electrophile. This annulation enabled the rapid assembly of valuable hydrocarbazolones from readily available indoles, and computational investigations were conducted to elucidate the reaction pathway and site-selectivity.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Jun Ueda, Shingo Harada, Mayu Kobayashi, Mai Yanagawa, Tetsuhiro Nemoto
Summary: A dual catalyst system consisting of maleic acid and Schreiner's thiourea was used to successfully synthesize a spiroindolenine core, providing a new approach for synthetic strategies that were previously difficult to achieve. Computational studies revealed a unique macrocyclic transition state that lowered the activation energy of the spirocyclization reaction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Masaya Nakajima, Yusuke Adachi, Tetsuhiro Nemoto
Summary: This study demonstrated the potential of computational simulation-based natural product syntheses as an indispensable resource in the field of organic synthesis. The authors reported the asymmetric total syntheses of several resveratrol dimers based on a comprehensive computational simulation of their biosynthetic pathways.
NATURE COMMUNICATIONS
(2022)
Correction
Multidisciplinary Sciences
Masaya Nakajima, Yusuke Adachi, Tetsuhiro Nemoto
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Takahito Kuribara, Masaya Nakajima, Tetsuhiro Nemoto
Summary: Ligand design plays a crucial role in enhancing the performance of light-enabled catalytic processes. In this study, the authors synthesized a visible-light-activated secondary phosphine oxide ligand and applied it to Pd-catalyzed radical cross-coupling reactions. Through molecular design aided by computational calculations, the ligand enables ligand-to-Pd(II) and Pd(0)-to-ligand single-electron transfer under visible-light irradiation, facilitating radical cross-coupling reactions.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Dongil Choi, Noa Takahashi, Haruka Maruoka, Shingo Harada, Alina Nastke, Harald Groeger, Tetsuhiro Nemoto
Summary: We developed an enantioselective synthetic method utilizing Ir-catalyzed asymmetric hydrogenation to introduce chirality at the benzylic position, followed by Pd-catalyzed cascade cyclization for tricyclic molecular framework construction and Ag nitrene-mediated C-H amination for tetrasubstituted carbon center creation. This method provides access to a functionalized seven-membered ring-fused indole skeleton with a hydroxymethyl branch in the tetrasubstituted carbon.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Yoshinori Hashimoto, Shingo Harada, Ryosuke Kato, Kotaro Ikeda, Jannis Nonnhoff, Harald Groeger, Tetsuhiro Nemoto
Summary: This study reported a catalytic approach for the formal synthesis of more than 20 types of sarpagine/macroline alkaloids, with two key steps being the amide insertion reaction using cheap copper and biocatalytic asymmetric desymmetrization.
Article
Chemistry, Multidisciplinary
Daria E. Kim, Yingchuan Zhu, Shingo Harada, Isaiah Aguilar, Abbigayle E. Cuomo, Minghao Wang, Timothy R. Newhouse
Summary: In this study, we successfully reported the total synthesis of the indole diterpenoid natural product shearilicine for the first time through an 11-step sequence using a generalizable precursor. The target molecule was obtained in an enantiospecific manner using a native chiral auxiliary strategy. The formation of the key carbazole substructure was achieved through a mild intramolecular Heck cyclization, which was promoted by noncovalent substrate-ligand and ligand-ligand interactions revealed by computational study.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Takahito Kuribara, Ayahito Kaneki, Yuma Mihara, Honoka Yuba, Tetsuhiro Nemoto
Summary: In this study, we describe a scandium-catalyzed regioselective synthesis of 5-carbonyl-4-hydroxybenzofurans via a phenol-directed intramolecular Friedel-Crafts reaction. This method was successfully applied for the total synthesis of furanoflavones. Experimental and theoretical calculations suggest that hydrogen bond interactions between the phenolic hydroxy group and the scandium complex enable regioselective intramolecular cyclization.
Article
Chemistry, Organic
Tetsuhiro Nemoto
Summary: This paper presents the advances in the synthesis of dragmacidin E, a bis-indole alkaloid isolated from a deep-water marine sponge in southern Australia. Synthetic studies conducted by the Funk, Feldman, Jia, and Nemoto groups are summarized, including the total synthesis of (±)-dragmacidin E achieved by Feldman et al. in 2011.
TETRAHEDRON LETTERS
(2023)
Article
Chemistry, Physical
Yu Matsuda, Masaya Nakajima, Tetsuhiro Nemoto
Summary: Transition metal-catalyzed photoreactions have been extensively reported, but the development of ligands for these reactions is limited. This study successfully synthesized acridine-containing PNP-pincer ligands and found that the platinum complex induced photoreactions of olefins under visible light irradiation. These reactions revealed unknown reactivities of transition metals that could not be achieved with existing well-known ligands.
Article
Chemistry, Organic
Mitsuru Ikeda, Hiroki Nakayama, Ayaka Kanda, Shingo Harada, Tetsuhiro Nemoto
Summary: This study explores the chemical synthesis of the core structure of Didymeline. A tricyclic molecule containing a spiro ring system was successfully synthesized, and enantioselective reactions under silver catalysis were investigated.
