Article
Chemistry, Physical
Michael Rauch, Jie Luo, Liat Avram, Yehoshoa Ben-David, David Milstein
Summary: This study reports a novel synthesis of thioesters and reveals the mechanism of their reverse hydrogenation. Experimental and computational approaches were used to elucidate the likely pathway of the reactions and discuss the impact of hydrogen gas pressure on selectivity. The study also identified the competitive nature of reactions between thiols and alcohols, as well as the stability differences of related catalysts.
Article
Chemistry, Organic
Delia Bellezza, Ramon J. Zaragoza, M. Jose Aurell, Rafael Ballesteros, Rafael Ballesteros-Garrido
Summary: The use of diols and anilines as reagents for indole synthesis is a challenging task in organic chemistry. Through the acceptorless dehydrogenative condensation method, heterocycles like indoles can be efficiently obtained. This study successfully reduced the excess of diols to 2 equivalents using heterogeneous catalysts, and explored pathways for the synthesis of various indole-like compounds.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Applied
Vinita Yadav, Ekambaram Balaraman, Santosh B. Mhaske
Summary: This study reports an air-stable, molecularly defined NNN-Mn(II) pincer complex catalyzing acceptorless dehydrogenative coupling of alcohols with indoles, successfully synthesizing various bis(indolyl)methane derivatives and important structurally relevant products. Mechanistic studies highlight the significance of the NH moiety in the complex and the crucial role of metal-ligand cooperation during catalysis.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Saranya Sundar, Ramesh Rengan, Anandaraj Pennamuthiriyan, David Semeril
Summary: A facile catalytic one-pot synthesis of N-acylhydrazones has been described using arene ruthenium (II) complexes. The method provides a wide range of N-acylhydrazones in good yields with high selectivity and functional group tolerance, without any alkylated products.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Yao Yu, Yang Wang, Bo Li, Yuqiang Tan, Huan Zhao, Zheyu Li, Chunran Zhang, Wenbo Ma
Summary: This article presents a convenient and effective method of ruthenium-catalyzed C-H/N-H annulations using vinylene carbonate as an oxidizing acetylene surrogate. The method is scalable and compatible with a wide range of functional groups, offering a economical approach to indole synthesis. Preliminary mechanistic studies support a reversible, acetate-assisted C-H ruthenation, followed by olefin insertion.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Bitan Sardar, Ramen Jamatia, Arup Samanta, Dipankar Srimani
Summary: An efficient Ru doped hydrotalcite catalyst was used for the N-alkylation of benzamides and sulfonamides with alcohols via borrowing hydrogen catalysis. The reaction showed good to excellent yields with various primary alcohols. Mechanistic studies revealed that the reaction proceeds via a borrowing hydrogen pathway. The catalyst also demonstrated the capability to directly synthesize quinazolinone and exhibited successful recyclability and high reactivity.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Masanori Tayu, Ryuta Watanabe, Satoshi Isogi, Nozomi Saito
Summary: Treatment of ynamides with a catalytic amount of TpRuCl(PPh3)(2) leads to the construction of indole scaffolds known as privileged structure motifs. This reaction involves a cascade of 1,2-rearrangement and cyclization carrying out C-C bond formation via a ruthenium vinylidene intermediate, as revealed by deuterium-labeling experiments. Furthermore, the transformation of multi-functionalized ynamide, derived from a practical drug molecule, demonstrates the high functional group tolerance of this reaction.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Physical
Siuli Das, Rakesh Mondal, Gargi Chakraborty, Amit Kumar Guin, Abhishek Das, Nanda D. Paul
Summary: The study presented a ligand-centered redox-controlled approach using a Zn(II)-stabilized azo-anion radical complex as a catalyst for efficient dehydrogenation of various N-heterocycles. The catalyst was found to be compatible with the cascade synthesis of N-heterocycles through dehydrogenative coupling of alcohols with other suitable coupling partners. Mechanistic investigation revealed that the dehydrogenation reactions proceed via a one-electron hydrogen atom transfer pathway and involve exclusive involvement of ligand-centered redox events with zinc acting only as the template.
Article
Chemistry, Physical
Sayan Kar, Yinjun Xie, Quan Quan Zhou, Yael Diskin-Posner, Yehoshoa Ben-David, David Milstein
Summary: A new method for amide bond synthesis under mild conditions using ruthenium PNNH complexes has been developed, avoiding the high reaction temperatures required by traditional methods and successfully synthesizing several commercially available pharmaceutical drugs.
Review
Chemistry, Multidisciplinary
Alexis Tabey, Pooja Y. Vemuri, Frederic W. Patureau
Summary: The high electronegativity of nitrogen presents challenges for N-N bond forming cross-coupling reactions, especially in an intermolecular fashion. Dehydrogenative N-N coupling reactions are advantageous in terms of step and atom economy, but require careful design of an oxidizing system to avoid unwanted side reactions. Despite the importance of N-N bonds in organic chemistry, only a few intermolecular hetero N-N cross-dehydrogenative couplings exist, highlighting the need for further research in this area.
Article
Chemistry, Multidisciplinary
Christopher Cremer, Monalisa Goswami, Christian K. Rank, Bas de Bruin, Frederic W. Patureau
Summary: This study reports the Te-II/Te-III-catalyzed dehydrogenative C-H phenothiazination of challenging phenols with electron-withdrawing substituents under mild aerobic conditions, achieving high yields. The unexpected Te-II/Te-III radical catalytic properties were characterized through cyclic voltammetry, EPR spectroscopy, kinetic experiments, and DFT calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Multidisciplinary
Serhiy M. Desenko, Mykola Yu. Gorobets, Victoria V. Lipson, Yana I. Sakhno, Valentyn A. Chebanov
Summary: Dihydroazolopyrimidines are an important class of heterocycles that are isosteric to natural purines and are therefore of great interest primarily as drug-like molecules. In the review, different ways to build dihydroazolopyrimidine systems from different building blocks are described, including aspects of green chemistry and non-classical activation methods. Information on the chemical properties of dihydroazolopyrimidines and the prospects for their use in the design of drugs of various profiles are also summarized in this review.
Article
Chemistry, Physical
Richard L. Wingad, Laurence Birch, Joshua Farndon, Jason Lee, Katy J. Pellow, Duncan F. Wass
Summary: Ruthenium complexes with tetradentate PNNP donor ligands exhibit different selectivity in Guerbet catalysis compared to bis bidentate PN complexes, producing a mixture of n-butanol (17%), sec-butanol (14%) and ethyl acetate (66%) instead of the usual 90%+ selectivity to n-butanol. Tridentate PNP ruthenium complexes also produce sec-butanol and achieve 71% selectivity to this isomer in optimized conditions. The same tri- and tetradentate complexes are efficient catalysts for converting methanol/ethanol mixtures to isobutanol with up to 97% selectivity.
Article
Chemistry, Physical
Xiangchao Xu, Yao Ai, Rongzhou Wang, Liping Liu, Jiazhi Yang, Feng Li
Summary: A ruthenium complex with a functional ligand was synthesized and found to be an efficient catalyst for the synthesis of quinolines. The NH units in the ligand were crucial for the catalytic activity. This research demonstrates the potential of metal-ligand bifunctional catalysts for acceptorless dehydrogenative reactions.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Jesus A. Luque-Urrutia, Tania Pelachs, Miquel Sola, Albert Poater
Summary: The mechanism of a base-metal-catalyzed synthesis of amides from alcohols and amines was studied using density functional theory calculations. The proposed reaction mechanism differs from the preliminary proposal, suggesting a simpler protocol. The catalyst first converts alcohols into aldehydes, which then react with amines to form the desired amides.
Article
Chemistry, Multidisciplinary
Hiroki Miura, Masahiro Nagao, Saburo Hosokawa, Tetsuya Shishido, Masashi Inoue, Kenji Wada
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
(2018)
Article
Chemistry, Applied
Tatsuhiro Fukutake, Kenji Wada, Gang Chuan Liu, Saburo Hosokawa, Qi Feng
Article
Biochemical Research Methods
Naoyuki Yamamoto, Natsumi Kawashima, Tomoya Kitazaki, Keita Mori, Hanyue Kang, Akira Nishiyama, Kenji Wada, Ichiro Ishimaru
JOURNAL OF BIOMEDICAL OPTICS
(2018)
Article
Chemistry, Physical
Kosuke Beppu, Saburo Hosokawa, Akito Demizu, Yudai Oshino, Kazuki Tamai, Kazuo Kato, Kenji Wada, Hiroyuki Asakura, Kentaro Teramura, Tsunehiro Tanaka
JOURNAL OF PHYSICAL CHEMISTRY C
(2018)
Article
Biochemical Research Methods
Tomoya Kitazaki, Natsumi Kawashima, Naoyuki Yamamoto, Hiroyuki Nomura, Hanyue Kang, Akira Nishiyama, Kenji Wada, Ichiro Ishimaru
JOURNAL OF BIOMEDICAL OPTICS
(2019)
Review
Chemistry, Multidisciplinary
Kenji Wada, Han Yu, Qi Feng
CHINESE CHEMICAL LETTERS
(2020)
Article
Chemistry, Physical
Tatsuhiro Fukutake, Kenji Wada, Han Yu, Saburo Hosokawa, Qi Feng
MOLECULAR CATALYSIS
(2019)
Review
Biochemistry & Molecular Biology
Hiroyuki Yamamoto, Kenji Wada, Jun Toyohara, Tetsuro Tago, Masanobu Ibaraki, Toshibumi Kinoshita, Yuka Yamamoto, Yoshihiro Nishiyama, Nobuyuki Kudomi
CARBOHYDRATE RESEARCH
(2019)
Article
Chemistry, Applied
Han Yu, Kenji Wada, Tatsuhiro Fukutake, Qi Feng, Shinobu Uemura, Kyosuke Isoda, Tomomi Hirai, Shinji Iwamoto
Summary: The modification of titania supports with phosphorus species greatly enhances the activity of iridium catalysts for the synthesis of benzimidazoles via hydrogen transfer. Different preparation methods, such as hydrothermal method and wet impregnation method, can effectively control the catalytic activity.
Article
Chemistry, Physical
Han Yu, Lin Ma, Kenji Wada, Ryohsuke Kurihara, Qi Feng, Shinobu Uemura, Kyosuke Isoda
Summary: This study successfully synthesized tertiary and secondary amines from aqueous ammonia and benzylic alcohols using a titania-supported iridium catalyst. The catalytic system showed good tolerance to atmospheric conditions and could efficiently produce the desired product within a short period. The activity of the catalyst was strongly influenced by the crystal structure of the titania supports for iridium catalysts.
Article
Energy & Fuels
Han Yu, Lin Ma, Kenji Wada, Ryohsuke Kurihara, Qi Feng, Shinobu Uemura, Kyosuke Isoda
Summary: Iridium catalysts supported on anatase with high surface area showed excellent activities for the acceptor-less dehydrogenation synthesis of benzoxazoles. The catalytic activity greatly depended on the titania supports, iridium precursors, and loading of iridium species. Highly dispersed iridium species of less than 2 nm in diameter were responsible for the excellent activity observed in the synthesis of benzoxazoles.
JOURNAL OF THE JAPAN PETROLEUM INSTITUTE
(2021)
Article
Chemistry, Analytical
Kosuke Nogo, Kou Ikejima, Wei Qi, Natsumi Kawashima, Tomoya Kitazaki, Satoru Adachi, Kenji Wada, Akira Nishiyama, Ichiro Ishimaru
Summary: This study developed a palm-sized LWIR hyperspectral camera for imaging-type two-dimensional Fourier spectroscopy, which could record the absorbance of black microplastics more quickly and effectively than traditional FPA-FT-IR systems, making it easier to use in the field or on a research vessel.
ANALYTICAL METHODS
(2021)
Article
Optics
Natsumi Kawashima, Tomoya Kitazaki, Kosuke Nogo, Akira Nishiyama, Kenji Wada, Ichiro Ishimaru
Article
Nanoscience & Nanotechnology
Wataru Asahi, Ryohsuke Kurihara, Kotaro Takeyama, Yui Umehara, Yu Kimura, Teruyuki Kondo, Kazuhito Tanabe
ACS APPLIED BIO MATERIALS
(2019)
Article
Chemistry, Multidisciplinary
Yuanjun Di, Tsutomu Yoshimura, Shun-ichi Naito, Yu Kimura, Teruyuki Kondo
