Article
Chemistry, Organic
Li-Hsiang Wang, Juntaro Nogami, Yuki Nagashima, Ken Tanaka
Summary: We have successfully synthesized axially chiral figure-eight spiro[9.9]-cycloparaphenylene (CPP) tetracarboxylates with high enantioselectivity (up to 75:25 er) via the cationic Rh-(I)/(R)-H-8-BINAP complex-catalyzed chemo-, regio-, and enantioselective intermolecular double [2 + 2 + 2] cycloaddition reaction of an achiral symmetric tetrayne with dialkyl acetylenedicarboxylates followed by reductive aromatization. The spiro[9.9]-CPP tetracarboxylates exhibit distorted structure with large dihedral and boat angles at the phthalate moieties and show weak aggregation-induced emission enhancement behavior.
Article
Chemistry, Inorganic & Nuclear
Kei Ikeda, Kazunari Yoshizawa, Yoshihito Shiota
Summary: The benzene hydroxylation catalyzed by ruthenium-substituted Keggin-type polyoxometalates was investigated, showing high chemoselectivity and the heteroatom effect on the reaction's activation free energy. Replacing Si with other elements can significantly affect the efficiency of the catalyst for benzene hydroxylation.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Sven Moersel, Rene Kellner, Andreas Hirsch
Summary: The synthesis of novel fluorinated hexa-peri-hexabenzocoronenes (HBCs) and their thioether-substituted analogs was reported, with the reaction time significantly reduced by using microwave assistance. Increasing fluorination or thioether-substituents led to a decrease in the extinction coefficient of the HBCs. Addition of thioether-moieties caused a shift in absorption and emission bands, while the nature of the thioether did not affect the optoelectronic properties. Oxidation to sulfone and formation of sulfonium salts further modified the electronic environment of the HBC core, resulting in decreased extinction coefficients and broadening of absorption and emission bands.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Dominika Fedorowicz, Katarzyna Slepokura, Julia Klak, Maciaj Witwicki, Janusz Gregolinski
Summary: One hexa- and two octanuclear Cu(ii) complexes were synthesized using different metal salts and a large tetraeicosaaza macrocycle. Characterization using elemental analysis, spectroscopy, crystallography, and magnetic susceptibility measurements revealed the unique coordination modes and nuclearity in these centrosymmetric complexes. In the case of the sulphate complex, both homo- and heterochiral arrangements of the macrocycle around the Cu(II) cations were observed.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
John M. Halford-McGuff, David B. Cordes, Allan J. B. Watson
Summary: A Rh-catalyzed [2+2+2] cycloaddition approach for the synthesis of BMIDA-functionalized arenes is developed to address the reactivity issues associated with internal alkynes. The method enables the access to highly functionalized borylated benzene scaffolds, and exhibits broad functional group compatibility and high yields. The utility of the products is demonstrated through their elaboration and synthesis of fused heterocycles via intramolecular Chan-Lam etherification and amination. The dominance of sterically controlled reactivity is described.
CHEMICAL COMMUNICATIONS
(2023)
Review
Chemistry, Physical
Yunfei Guo, Mikko Muuronen, Frederic Lucas, Rint P. P. Sijbesma, Zeljko Tomovic
Summary: The formation of isocyanurate via cyclotrimerization of isocyanates is widely reported to provide polyurethane materials with improved properties. The review summarizes catalysts for the cyclotrimerization of isocyanates, categorizing them into two main classes and providing detailed information on catalyst structures, reaction conditions, and trimerization efficiency. The review aims to stimulate the design of more efficient catalysts and further understanding of the trimerization mechanism.
Article
Chemistry, Multidisciplinary
Takeshi Yatabe, Tamon Tome, Yukina Takahashi, Takahiro Matsumoto, Ki-Seok Yoon, Hidetaka Nakai, Seiji Ogo
Summary: This study presents the first example of C-H arylation of benzene under mild conditions using H-2 as an electron source {with turnover numbers (TONs) of 0.7-2.0 for 24 hours}. The reaction relies on a Rh-based electron storage catalyst, operates at room temperature and in aqueous solution, and effectively suppresses unwanted side reactions by rendering H-2 inactive during the radical transfer step.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Energy & Fuels
Priyanka Tavhare, Elby Titus, Ajay Chaudhari
Summary: The hydrogen storage properties of metal doped benzene complexes were found to vary depending on the positions of boron atom substitution. Ti-doped boron substituted complexes showed higher H2 uptake capacity and stronger interaction with adsorbed hydrogen molecules compared to Li, Be, and Ca-doped complexes, making them promising materials for hydrogen storage.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Chemistry, Multidisciplinary
Yanjun Li, Shichao Li, Yan Kong
Summary: The effects of preparation conditions on supported catalysts for the hydroxylation of benzene were investigated. Catalysts prepared using ethanol as the solvent showed the highest phenol yield, a high TOF value, and good reusability. This work provides an effective and convenient strategy for the preparation of a new catalyst for hydroxylation of benzene to phenol.
Article
Chemistry, Organic
Jannis Volkmann, Daniel Kohrs, Felix Bernt, Hermann A. Wegner
Summary: We report the synthesis and investigation of a substituted [10]cycloparaphenylene (CPP) incorporating a diethylphthalane unit. An efficient strategy based on symmetric built-up starting with propargyl ether was developed for the synthesis. The straightforward synthesis required overcoming unexpected obstacles within the [2 + 2 + 2] cycloaddition, protection, and aromatization. The results provide insights for accessing CPPs with highly substituted subunits. A seven-step synthesis with an overall yield of 8% was used to obtain the target nanoring, including good to excellent yields for the critical macrocyclization and aromatization. The synthesized nanohoop exhibits a hypsochromic shift compared to the unsubstituted [10]CPP, possibly due to an increased torsion angle between the bivalent substituted phenyl moieties and the adjacent units.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Ruiqin Zhang, Yuxin Ding, Renchao Ma, Xuqiong Xiao, Rener Chen, Lei Wang, Yongmin Ma
Summary: An efficient synthesis method for multi-substituted pyridines and pyrroles from aryl methyl ketones with 1-amino-2-methylpropan-2-ol and 1,2-diamino-2-methylpropane has been developed. The reactions involve cleavage of a C-N bond and formation of two new bonds (C-C bond and C-N bond) through an oxidative cyclization process promoted by I-2/PhNO2. The selective cleavage occurs at the C-N bond adjacent to the primary carbon of 1,2-diamino-2-methylpropane.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Maotong Xu, Tongtong Wang, Zheng-Wang Qu, Stefan Grimme, Douglas W. Stephan
Summary: This study presents a transition metal-free method for synthesizing hexa-substituted benzene derivatives from simple C1 feedstocks, which is viable on a gram scale and allows for the incorporation of C-13 labels. The mechanisms of these reactions are elucidated through extensive density functional theory computations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Engineering, Environmental
Xi Liu, Jianjun Chen, Guochen Zhang, Yang Wu, Puqing Shen, Lin Zhong, Yaoqiang Chen
Summary: Three Ce-modified Pd-Rh bimetallic catalysts were prepared using different methods, with the catalyst prepared by deposition-precipitation (DP) demonstrating the highest catalytic activity and metal dispersion at high temperatures. The interactions between Pd-Rh and Pd-Ce can be adjusted to enhance the performance of Pd-Rh three-way catalyst for NGVs exhaust purification.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Engineering, Environmental
Yao Sheng, Yang Liu, Yuchen Yin, Xiujing Zou, Jiaan Ren, Baoqin Wu, Xueguang Wang, Xionggang Lu
Summary: A activated carbon supported Pt-Rh alloy catalyst was synthesized using a facile incipient wetness impregnation strategy, and showed improved activity and selectivity for the hydrogenation of nitrobenzene to p-aminophenol. The presence of Rh promoted the formation of well dispersed Pt-Rh bimetallic nanoparticles on the catalyst surface, accompanied by possible electron transfer from Rh to Pt. Density functional theory calculations indicated that the electron-rich Pt inhibited the adsorption of the generated phenylhydroxylamine intermediate, resulting in excellent selectivity for p-aminophenol.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Yair Cohen, Andre U. Augustin, Laura Levy, Peter G. Jones, Daniel B. Werz, Ilan Marek
Summary: The regio- and diastereoselective copper-catalyzed carbomagnesiation reaction of cyclopropenes provides an easy and efficient access to novel persubstituted cyclopropyl cores with complete regio- and diastereoselectivity, despite the highly strained nature of cyclopropanes possessing three vicinal quaternary carbon stereocenters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Yuji Kurimoto, Jun Yamashita, Koichi Mitsudo, Eisuke Sato, Seiji Suga
Summary: The first electrochemical synthesis of diarylphosphole oxides (DPOs) was achieved under mild conditions using commercially available and inexpensive DABCO as a hydrogen atom transfer mediator. The procedure resulted in moderate to good yields of various DPOs and can also be used for the synthesis of six-membered phosphacycles. Mechanistic studies suggested that the reaction proceeds via an electro-generated phosphinyl radical.
Article
Chemistry, Organic
Eisuke Sato, Mayu Fujii, Hiroki Tanaka, Koichi Mitsudo, Masaru Kondo, Shinobu Takizawa, Hiroaki Sasai, Takeshi Washio, Kazunori Ishikawa, Seiji Suga
Summary: This paper presents an electrochemically initiated cyanosilylation of carbonyl compounds, with machine learning-assisted optimization to determine the best productivity conditions.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Applied
Masafumi Yano, Yoshinori Inada, Yuki Hayashi, Misaki Nakai, Koichi Mitsudo, Yukiyasu Kashiwagi
Summary: A triphenylamine compound with three benzothiophene rings was synthesized with a high yield, showing absorption at 386 nm and NIR-II absorption at 1213 nm after one-electron oxidation. This compound demonstrated a high fluorescence quantum yield and thermostability.
Article
Chemistry, Multidisciplinary
Eisuke Sato, Yuta Niki, Koichi Mitsudo, Seiji Suga
Summary: An oxidative trimerization of catechol and its derivatives leads to the formation of triphenylene derivatives. However, the precipitation of a radical cation pair during overoxidation hinders efficient synthesis. A reductive workup strategy and alternating current (AC) electrolysis offer effective solutions.
Article
Chemistry, Multidisciplinary
Hiroki Mandai, Yuichiro Matsuura, Fatin Mahfuzah Binti Johari, Koichi Mitsudo, Seiji Suga
Summary: An efficient method for silylation of alcohols using DMAPO as a reagent has been developed. Experimental results showed that the silylation of phenolic hydroxy group was much faster than that of primary alcohols, which might be attributed to the acidity (pKa value) of the hydroxy group.
Article
Chemistry, Organic
Koichi Mitsudo, Haruka Inoue, Yuta Niki, Eisuke Sato, Seiji Suga
Summary: This paper describes the electrochemical hydrogenation of enones using a proton-exchange membrane reactor. The reduction of enones proceeded smoothly under mild conditions to produce ketones or alcohols. The reaction showed chemoselectivity with the use of different cathode catalysts (Pd/C or Ir/C).
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Eisuke Sato, Sae Kangawa, Koich Mitsudo, Seiji Suga
Summary: The semi-pinacol rearrangement of tetrahydro-P-carbolines to afford 3-spirooxindoles was efficiently promoted by anodically generated bromonium ion equivalent as a halogen mediator.
Letter
Chemistry, Organic
Koichi Mitsudo, Yuri Tachibana, Eisuke Sato, Seiji Suga
Summary: Electrochemical synthesis of dibenzothiophene derivatives was achieved by efficiently converting several bis(biaryl) disulfides to dibenzothiophenes via electrochemical oxidation. The use of Bu4NBr as a halogen mediator was essential, leading to the successful synthesis of diverse dibenzothiophene derivatives.
Article
Chemistry, Applied
Eisuke Sato, Gaku Tachiwaki, Mayu Fujii, Koichi Mitsudo, Takashi Washio, Shinobu Takizawa, Seiji Suga
Summary: The use of a flow reactor in electrolysis allows for efficient and scalable synthesis, which is typically challenging with batch reactors. We successfully achieved electrochemical carbon-Ferrier rearrangement using catalytic anodic oxidation in an electrochemical flow reactor. Gaussian process regression (GPR), a machine learning method, enabled the adjustment of numerical parameters derived from the flow reactor. GPR also facilitated the construction of two models for estimating yields and productivity, allowing for rational selection of reaction conditions.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2023)
Article
Chemistry, Organic
Koichi Mitsudo, Yasuyuki Okumura, Kotaro Yohena, Yuji Kurimoto, Eisuke Sato, Seiji Suga
Summary: Electrochemical dehydrogenative C-O bond formation was achieved for the synthesis of sultones. In the presence of K2CO3 and H2O, constant current electrolysis of [1,1'-biphenyl]-2-sulfonyl chloride resulted in quantitative formation of aryl-fused sultone. Control experiments suggest that electrochemical oxidation of sulfonates generates sulfo radical intermediates.
Article
Chemistry, Organic
Koichi Mitsudo, Keisuke Shigemori, Taro Shibata, Hiroki Mandai, Eisuke Sato, Seiji Suga
Summary: An electrochemical cross-coupling reaction between arylboronic esters and aryllithiums was developed, with the essential role of Br- in the electrolyte. NaBr was chosen as the electrolyte for its inexpensiveness and abundance, serving as a halogen mediator. Under mild conditions, the reaction yielded biaryls.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Eisuke Sato, Ayaka Yukiue, Koichi Mitsudo, Seiji Suga
Summary: Anodic oxidation was used to achieve the aromatization of 1,2,3,4-tetrahydrocarbazoles. Nitrogen-protected tetrahydrocarbazoles were converted to carbazoles with the use of bromide as a mediator. The presence of AcOH and the inexpensive bromide source LiBr allowed for efficient transformation.
Article
Electrochemistry
Eisuke Sato, Mayu Fujii, Koichi Mitsudo, Seiji Suga
Summary: In this study, the alkynylation of aldehydes initiated by cathodic reduction was investigated. It was found that only a small amount of catalytic current was needed to completely consume the starting material. Cyclic voltammetry and control experiments suggested that the electron-generated base from the cathodic reduction of benzaldehyde promoted the alkynylation reaction.
Article
Chemistry, Organic
Hiroki Mandai, Kosuke Ashihara, Koichi Mitsudo, Seiji Suga
Summary: In this study, an efficient enantioselective acylative desymmetrization of glycerol was achieved using a chiral DMAP derivative. The reaction showed moderate to good enantioselectivity with only 0.1 mol% of the catalyst required. Control experiments confirmed the selective nature of the acylation process.
Article
Chemistry, Multidisciplinary
Kotaro Obayashi, Keiichi Imato, Satoshi Aoyama, Toshiaki Enoki, Seiji Akiyama, Mio Ishida, Seiji Suga, Koichi Mitsudo, Yousuke Ooyama
Summary: The study focused on the design and synthesis of three 4,4'-bibenzo[c]thiophene derivatives, with subsequent characterization using various analytical techniques. Variations in photophysical properties and energy levels were observed in both solution and solid state environments for the derivatives.
Article
Chemistry, Organic
Fuying Zhu, Yamei Lin
Summary: In this study, a low-metal iron-supported catalyst (Fe20/NC-Mg) was reported for the efficient synthesis of quinoxaline compounds, using water as a solvent and without additional bases. The synergistic effect of FeNx site and Mg (OH)2 nanorods in the catalyst played a key role in achieving high yields (82-91%) in 16 examples. The gram-level synthesis and reusability of the catalysts after four cycles demonstrated its industrial application potential.
Article
Chemistry, Organic
Mikhail Kozlov, Alexey Tyurin, Andrey Dmitrenok, Vyacheslav Rusak, Aleksander Fedorov, Igor Zavarzin, Yulia Volkova
Summary: This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.
Article
Chemistry, Organic
Jisna Jose, Thomas Mathew
Summary: 2-Cyclopentenone and its derivatives are highly esteemed synthetic intermediates with exceptional utility in organic synthesis. They are favored structural motifs in numerous pharmaceutical drugs and natural products, highlighting their significance. The review discusses the various methods used to synthesize cyclopentenones from 2016 to 2023.
