Article
Green & Sustainable Science & Technology
Ayman Akhdar, Killian Onida, Nam Duc Vu, Kevin Grollier, Sebastien Norsic, Christophe Boisson, Franck D'Agosto, Nicolas Duguet
Summary: A range of thermomorphic polyethylene-supported organocatalysts were prepared with good yields and high functionality, and studied for the ring opening of epoxidized methyl oleate with CO2. The optimized conditions were applied to a range of epoxidized fatty acids, showing good yields of the corresponding carbonates. Catalyst recycling study demonstrated no significant loss of activity, making fatty carbonates important intermediates for non-isocyanate polyurethanes (NIPUs) preparation.
ADVANCED SUSTAINABLE SYSTEMS
(2021)
Article
Chemistry, Multidisciplinary
Yan-Lan Liu, Guang-Hui He, Ye Liu, Xiao-Bing Lu
Summary: The enantioselective resolution copolymerization of racemic aromatic 2,3-disubstituted cis-epoxides and CO2 using enantiopure dinuclear cobalt(III) complexes as catalyst yielded polycarbonates with completely alternating structure and good enantioselectivity in the range of 70% to 97% ee. The copolymer selectivity is correlated well with the Hammett substituent constant, and the highest polymer selectivity of 98% was found in the system using the epoxides bearing an electron-donating group on the benzene ring.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Polymer Science
Chengdong Lv, Guangqiang Xu, Rulin Yang, Li Zhou, Qinggang Wang
Summary: The asymmetric kinetic resolution polymerization catalyzed by chiral phosphoric acid can produce stereogradient polycaprolactones with controlled properties such as chain-end fidelity, molecular weights, and molar mass dispersity. The resulting PCLs exhibit high quality thermal properties, viscoelasticity, and degradation characteristics.
Article
Engineering, Chemical
Zahra Eshaghi Gorji, Abbas Ali Khodadadi, Siavash Riahi, Timo Repo, Yadollah Mortazavi
Summary: This research developed efficient and affordable bifunctional organocatalysts for the cycloaddition reaction of CO2 with epoxides, achieving high product yield and catalytic activity. The study provided insights into the kinetics and thermodynamics of the reaction, as well as proposed a mechanism. Analysis of activation energy and free energy confirmed a non-spontaneous, endergonic reaction controlled by kinetics.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2021)
Article
Chemistry, Organic
Zhuo-Qun Li, Yao-Yao Zhang, Yu-Jia Zheng, Bo Li, Guang-Peng Wu
Summary: This study systematically investigated the impact of different chain lengths, nucleophilic anions, and substituents on the catalytic performance of bifunctional catalysts in fixing CO2. The optimal spatial effect for the coupling of epoxides and CO2 was found to be the spacer length of tetramethylene. Additionally, the crystal structure analysis revealed the existence of interaction forces and hydrogen bonding interactions within the catalyst molecule. These findings provide important insights for the optimization of existing catalysts and the design of future catalysts.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Ria Ayu Pramudita, Ken Motokura
Summary: This article presents the current development of utilizing hydrosilanes in the chemical reduction of CO2, with a focus on organic catalysts. The use of heterogeneous organocatalysts with precisely designed active sites is emphasized for their recyclability and higher efficiency in these transformations.
Article
Chemistry, Multidisciplinary
Yan Yu, Bang Gao, Ye Liu, Xiao-Bing Lu
Summary: This study reports a highly efficient chemical recycling method to depolymerize CO2-based alicyclic polycarbonates into epoxide monomers. The method is solvent-free and exhibits excellent reactivity and high epoxide monomer selectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Engineering, Environmental
Longqiang Xiao, Yiming Lai, Qianyu Song, Jingyu Cai, Yulai Zhao, Linxi Hou
Summary: A series of polymers were synthesized by copolymerization of vinyl functionalized polyhedral oligomeric silsesquioxanes (POSS) with vinylimidazole based linker, by adjusting the molar ratio of the two monomers. These POSS-based polymers were found to be efficient catalysts for the cycloaddition reaction of CO2 with various epoxides, producing cyclic carbonates with a high conversion of up to 97.1% under atmospheric pressure without solvent and co-catalyst. Moreover, the synthesized polymers significantly reduced the activation energy of the cycloaddition reaction of CO2 and could be recycled up to 5 times without a decrease in catalytic performance.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Qianwen Jiang, Dekun Zhang, Mengyao Tang, Hua Liu, Xiaoyu Yang
Summary: A novel kinetic resolution method has been developed for the synthesis of 3,3-disubstituted indolines with C3-quaternary stereocenters. The method utilizes triazane formation reaction and dehydrogenation reaction to achieve high enantioselectivity. This method has significant synthetic value.
SCIENCE CHINA-CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Ala'a F. Eftaiha, Abdussalam K. Qaroush, Areej K. Hasan, Wissam Helal, Feda'a M. Al-Qaisi
Summary: This study focuses on CO2 fixation using imidazolium-based catalysts for the production of cyclic carbonates, demonstrating high reactivity and selectivity. Various onium salts were synthesized and characterized, showing a detailed mechanism for the cycloaddition reaction.
REACTION CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Organic
Song Sun, Zhaobin Wang, Shijia Li, Cong Zhou, Lijuan Song, Hai Huang, Jianwei Sun
Summary: This study presents the first organocatalytic kinetic resolution of unactivated aziridines using sulfur nucleophiles, achieving excellent enantioselectivity. A chiral phosphoric acid was identified as an efficient catalyst for intermolecular ring opening under mild conditions, providing highly enantioenriched beta-amino thioethers and aziridines as useful synthetic building blocks.
Review
Polymer Science
Suleiman Gani Musa, Zulkifli Merican Aljunid Merican, Omid Akbarzadeh
Summary: With the escalating issue of global warming, efforts are being made towards achieving a carbon-neutral environment by utilizing non-fossil fuel sources such as solar, nuclear, and biomass energy. Metal-organic frameworks are being explored as potential catalysts for converting CO2 into organic carbonates, given their unique features and ease of synthesis.
Review
Biotechnology & Applied Microbiology
Chenming Huang, Junling Liu, Jiali Fang, Xian Jia, Zhendong Zheng, Song You, Bin Qin
Summary: This review discusses the advances in the research area of KRED-catalyzed asymmetric synthesis for biomanufacturing of chiral chemicals with at least two chiral centers through the kinetic resolution (KR) approach and the dynamic kinetic resolution (DKR) approach.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Feng Zhang, Safak Bulut, Xiaojun Shen, Minghua Dong, Yanyan Wang, Xiaomeng Cheng, Huizhen Liu, Buxing Han
Summary: Bifunctional organocatalysts with diamine and carboxylic acid groups were used to prepare cyclic carbonates through cycloaddition reactions, showing excellent catalytic activities with high yields and selectivities. This metal-free system provides a promising halogen-free and green pathway for the synthesis of cyclic carbonates from CO2 and epoxides.
Article
Chemistry, Multidisciplinary
Pieter J. Gilissen, Annemiek D. Slootbeek, Jiangkun Ouyang, Nicolas Vanthuyne, Rob Bakker, Johannes A. A. W. Elemans, Roeland J. M. Nolte
Summary: The construction of macromolecular hosts capable of threading chiral guests in a stereoselective manner is a challenge. The asymmetric synthesis of two enantiomeric C-2-symmetric porphyrin macrocyclic hosts has been described, showing kinetic selectivity for different viologen guests. The presence or absence of chiral termini in the viologen guests affects the kinetic selectivity of the threading process onto the hosts.
Article
Chemistry, Multidisciplinary
Kazuto Takaishi, Yusuke Nakatsuka, Hitomi Asano, Yuya Yamada, Tadashi Ema
Summary: A new family of chiral complex dyes was synthesized with ruthenium(II) complexes bearing three axially chiral bipyridyl ligands. The Delta-(S)- and ?-(S)-diastereomers exhibited different circularly polarized phosphorescence properties, with the ?-(S)-isomer showing significant CH/pi interactions to suppress distortion in the excited state T-1.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Takumi Murata, Mahoko Hiyoshi, Shinsuke Maekawa, Yuta Saiki, Manussada Ratanasak, Jun-ya Hasegawa, Tadashi Ema
Summary: BPh3 catalyst enables the N-methylation of secondary amines and C-methylenation of N,N-dimethylanilines or 1-methylindoles in the presence of CO2 and PhSiH3 without solvent. Additionally, a cascade reaction from 1-methyl-2-oxindole to 3,3'-methylenebis(1-methylindole) was observed.
Article
Chemistry, Multidisciplinary
Kazuto Takaishi, Sho Murakami, Fumiya Yoshinami, Tadashi Ema
Summary: A series of D-2-symmetric macrocycles composed of alternately linked pyrene and binaphthyl moieties have been synthesized, among which a pyrenophane with ether linkers at the 2,7-positions of pyrenes demonstrated intense circularly polarized luminescence (CPL). The CPL exhibited by this pyrenophane is the highest among excimers and is insensitive to temperature, solvent, or concentration. The CPL originated from a twisting pyrene excimer with left-handed twist produced by (R)-binaphthyl moieties, showing a strong relationship between the electric and magnetic transition dipole moments.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Manussada Ratanasak, Takumi Murata, Taishin Adachi, Jun-ya Hasegawa, Tadashi Ema
Summary: BPh3 catalyzes the N-methylation of secondary amines and the C-methylenation of N,N-dimethylanilines or 1-methylindoles in the presence of CO2 and PhSiH3. The mechanism involves the activation of PhSiH3 by BPh3 to generate key CO2-derived species for the N-methylation reaction. DFT calculations also suggest other mechanisms involving water for the activation of PhSiH3.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Koichi Nakaoka, Chao Guo, Yuta Saiki, Shin Furukawa, Tadashi Ema
Summary: In this study, TBAA and Cu(OAc)(2) were used as a binary catalytic system for the solvent-free N-formylation of amines with CO2 and PhSiH3. This catalysis not only synthesized enamines, aldehydes, and nitriles, but also formed C-H and C-N bonds, achieving a one-pot synthesis.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Chihiro Maeda, Hina Inoue, Ayano Ichiki, Takumi Okihara, Tadashi Ema
Summary: Bifunctional aluminum porphyrins can catalyze the conversion of oxetane and CO2 into TMC and PTMC. The catalytic activity is influenced by the Al3+ ion, while the selectivity is controlled by the counteranions. Different TMC compounds can be prepared by using various oxetane derivatives.
Review
Chemistry, Medicinal
Kazuto Takaishi, Chihiro Maeda, Tadashi Ema
Summary: Circularly polarized luminescence (CPL) dyes, recognized as new generation materials, are actively being developed with the help of molecular recognition systems. CPL can be induced through the mixing of different characteristics of host and guest molecules, providing a more efficient alternative to covalent bonding methods in constructing ordered chiral structures.
Article
Chemistry, Multidisciplinary
Chihiro Maeda, Issa Yasutomo, Kazuto Takaishi, Tadashi Ema
Summary: In this article, recent progress in functional dyes showing circularly polarized luminescence (CPL) containing porphyrins or phthalocyanines is summarized. The CPL-active systems are classified into four categories: (i) porphyrins with chiral sources; (ii) axially chiral porphyrin dimers; (iii) self-assembled porphyrins; (iv) porphyrin-sensitized CPL dyes.
JOURNAL OF PORPHYRINS AND PHTHALOCYANINES
(2023)
Article
Chemistry, Applied
Fan Yang, Yuta Saiki, Koichi Nakaoka, Tadashi Ema
Summary: This study reported the solvent-free N-formylation reaction catalyzed by Cu(OAc)(2), which used CO2 and phenylsilane to react with 2-(methylamino)pyridine and produced N-methyl-N-(2-pyridyl)formamide. The improved solubility of copper ion and enhanced nucleophilicity of acetate ion played positive roles in the activation of phenylsilane.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Chihiro Maeda, Koki Akiyama, Tadashi Ema
Summary: Oxidation of dihydroxyhetero[7]-helicenes resulted in the formation of dihetero[8]-circulenesvia simultaneous C-C coupling and dehydrative furan formation. The synthesized pristine dihetero[8]-circulenes were characterized for the first time, with X-ray crystal structures and DFT-optimized structures revealing distorted saddle-like structures. The degree of distortion was found to be correlated with the photophysical properties.
Article
Chemistry, Organic
Kazuto Takaishi, Ritsuki Nishimura, Yuha Toda, Hajime Morishita, Tadashi Ema
Summary: Catalytic CO2 reduction with phenylsilane under solvent-free conditions was utilized to synthesize 3,4-dihydropyrans from beta dicarbonyl compounds and styrenes in a one-pot reaction. The synthesis involves three steps: (1) formation of bis(silyl)acetal from CO2 and phenylsilane, followed by a domino reaction of (2) Knoevenagel condensation and (3) inverse-electron-demand oxa-Diels-Alder reaction. The first step is catalyzed by a pentanuclear ZnII complex (0.07 mol %) to generate bis(silyl)acetals, which are then hydrolyzed into formaldehyde for the second step.
