Article
Green & Sustainable Science & Technology
Chihe Sun, Yun Hu, Fubao Sun, Yahui Sun, Guojie Song, Haixing Chang, Siriporn Lunprom
Summary: The study prepared a heterogeneous cobalt doping Zn/Al complex oxide catalyst by a simple birch-templating method and successfully applied it to the transesterification of jatropha oil with methanol, achieving a high biodiesel yield. The crystalline particles from the templating method were uniformly distributed on the catalyst surface, forming a well-defined tiled network with large amounts of grain-free pores.
Article
Chemistry, Organic
Krishanu Mondal, Susanta Patra, Pallabi Halder, Narottam Mukhopadhyay, Parthasarathi Das
Summary: CuF2/DMAP has been established as an excellent catalytic system for vinylsilane-promoted N-vinylation of amides and azoles at room temperature without an external fluoride source. A mechanism has been proposed based on the isolation of reactive intermediate [Cu(DMAP)4Cl2], fluoride ion-assisted transmetalation, and ultraviolet-visible spectroscopic studies. The catalytic efficiency of the synthesized and structurally characterized [Cu(DMAP)4Cl2] complex has been demonstrated.
Article
Polymer Science
Jiaqi Qiu, Fuliang Meng, Maolin Wang, Jinjin Huang, Chengzhan Wang, Xiao Li, Guang Yang, Zan Hua, Tao Chen
Summary: The study introduces a strategy of fabricating highly efficient and recyclable nanoreactors through macromolecular self-assembly, which exhibit excellent dispersity and catalytic activity in water, achieving high conversion and selectivity in alcohol acylation reactions. The high catalytic efficiency of the nanoreactors may be attributed to enhanced interaction between reactants and catalyst, mimicking enzyme-like behavior. Additionally, the catalyst can be easily recovered and reused multiple times with high activity.
Article
Materials Science, Multidisciplinary
Anupam Singha Roy, Aby Cheruvathoor Poulose, Aristides Bakandritsos, Rajender S. Varma, Michal Otyepka
Summary: 2D carbon materials like graphene derivatives have been explored as catalysts for biodiesel production due to their exceptional properties, but challenges such as irreversible agglomeration, low bulk density, and poor dispersibility in organic solvents limit their applications as catalysts or heterogeneous catalysts support.
APPLIED MATERIALS TODAY
(2021)
Article
Engineering, Environmental
Ricardo Rodriguez-Ramirez, Fabiola S. Sosa-Rodriguez, Jorge Vazquez-Arenas
Summary: Zinc Oxide-co-Sodium Zirconate (ZnO.Na2ZrO3) composite catalyst is synthesized for the fast transesterification of triglycerides in soybean oil, showing competitive performance compared to caustic soda. The synthesized catalyst exhibits enhanced properties and can achieve 97% biodiesel conversion under optimal conditions.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Chemistry, Physical
Pierre-Louis Lagueux-Tremblay, Celestin Augereau, Pranav Nair, Kwan Ming Tam, Bruce A. Arndtsen
Summary: The use of metal catalysis to form potent acylating agents is an important approach to expand the application of carbonylation reactions. However, the reductive elimination of these reactive products has been a challenge, making these reactions often high temperature, high pressure, and limited in scope. In this study, a mild and versatile palladium catalyzed carbonylative method was developed to generate electrophilic acyl-DMAP salts by exploiting the counterion. The weakly coordinating triflate anion was found to destabilize Pd(II) and enable irreversible reductive elimination, while ligand design facilitated the rapid activation of aryl or vinyl triflates. This approach allows palladium catalyzed carbonylations to be carried out under exceptionally mild conditions, with low catalyst loading and using readily available C(sp2)-triflate reagents.
Article
Chemistry, Physical
Pierre-Louis Lagueux-Tremblay, Celestin Augereau, Pranav Nair, Kwan Ming Tam, Bruce A. Arndtsen
Summary: The use of metal catalysis to form potent acylating agents is an important method to broaden the applicability of carbonylation reactions. However, the reductive elimination of these reactive products has presented a challenge, making the reactions often high temperature and high pressure, and limited in scope. In this study, a mild and versatile palladium catalyzed carbonylative method was developed to generate electrophilic acyl-DMAP salts. The use of triflate anion as a counterion destabilizes Pd(II) and allows for irreversible reductive elimination, while ligand design enables the rapid activation of aryl or vinyl triflates.
Article
Energy & Fuels
Linsheng Bai, Limin Wang, Yujing Liu, Zhongqiu Liu, Anguo Ying
Summary: This study investigated the supported polymeric ionic liquids as heterogeneous catalysts for the transesterification of methanol and soybean oil to produce biodiesel. The modified fibers showed sufficient active sites and mechanical strength for the catalytic application. The fiber catalyst with 8 carbon alkyl chains and OMe anion exhibited the optimal catalytic efficiency with a biodiesel yield of 95.4%.
Article
Chemistry, Physical
Helapiyumi Weerathunga, Cheng Tang, Aidan J. Brock, Sarina Sarina, Tony Wang, Qiong Liu, Huai-Yong Zhu, Aijun Du, Eric R. Waclawik
Summary: Selective oxidation of alcohols is crucial for fine chemical production, and the photocatalytic oxidation of benzyl alcohol using ZnO nanocrystals was investigated in this study. Different shapes of ZnO nanocrystals displayed varying kinetics for the benzyl alcohol oxidation reaction, with nanocones showing the highest conversion rate. The {10 (1) over bar1} facet of ZnO was found to expose undercoordinated O atoms, leading to the highest adsorption of benzyl alcohol and ultimately resulting in 100% selectivity for benzaldehyde as the product.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Food Science & Technology
Min Zhang, Weibo Lu, Huicheng Yang, Pingan Zheng, Hujun Xie, Kang Chen, Jing Xue, Qing Shen
Summary: Through transesterification reactions, it was found that enrichment of EPA and DHA was superior with enzyme-catalysis compared to chemical catalysis.
LWT-FOOD SCIENCE AND TECHNOLOGY
(2021)
Review
Chemistry, Multidisciplinary
Joachim F. R. Van Guyse, Yann Bernhard, Annelore Podevyn, Richard Hoogenboom
Summary: Non-activated esters have prominent features in polymer science but their low reactivity prevents their direct use in post-polymerization modification. However, utilizing non-activated esters for modification is still a valuable opportunity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yue Hu, Shiyun Zhang, Juanfang Xu, Yuan Liu, Aiai Yu, Jun Qian, Yinjun Xie
Summary: The study demonstrates an efficient strategy for degrading diverse waste polyesters at low temperature and pressure, utilizing a quinaldine-based Ru complex for initial transesterification and hydrogenation. The catalysts can be hydrogenated to an active species, which shows strong viability and high activity in protic solvent. Methanol plays a crucial role in promoting reaction efficiency throughout the process.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Engineering, Chemical
Han Han, Xue Ye, Jie Yao, Xinhua Gao, Jinghao Yu, Lisheng Guo, Jie Li
Summary: A catalyst of alkali metal K anchored on the CuO/ZnO oxide is rationally designed to improve the activation efficiency of methanol for the synthesis of dimethyl carbonate (DMC). The addition of Lewis base K enhances the dissociation of methanol and combined with Lewis acid CuO/ZnO oxide, resulting in high catalytic activity and selectivity for DMC.
Article
Engineering, Environmental
Adeyinka Sikiru Yusuff, Afeez Olayinka Gbadamosi, Lekan Taofeek Popoola
Summary: This study developed a new eco-friendly solid catalyst from anthill-zinc modification for methanolysis of low-grade feedstock to produce biodiesel. The optimized conditions for the reaction resulted in a high biodiesel yield of 83.16%, showing good agreement with the predicted value. The catalyst exhibited better stability after being regenerated and reused for six cycles, indicating its potential for economical biofuel production from waste products.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Chemistry, Physical
Julia S. Schulze, Raoul D. Brand, Joachim G. C. Hering, Luise M. Riegger, Peter R. Schreiner, Bernd M. Smarsly
Summary: In this study, the immobilization of 4-dimethylaminopyridine (DMAP) on mesoporous silica particles and macro-mesoporous silica monoliths for continuous flow synthesis was reported. The immobilized DMAP derivatives were characterized and their catalytic performance was studied. The results showed that both materials achieved high conversion rates in continuous flow experiments, with the macro-mesoporous silica monoliths exhibiting lower pressures and higher turnover rates compared to packed bed reactors.
Article
Chemistry, Multidisciplinary
Dimitrije Djukanovic, Maximilian A. Ganiek, Kohei Nishi, Konstantin Karaghiosoff, Kazushi Mashima, Paul Knochel
Summary: A new convenient method for the preparation of dicarbamoylzincs is reported in this study. The target compounds were obtained by reacting ZnCl2 and formamides or TMP2Zn with formamides. This method is compatible with sensitive functional groups such as esters, ketones, or nitro groups. The reaction of these dicarbamoylzincs with various functionalized allylic, benzylic, aryl, alkenyl compounds, acid chlorides, aldehydes, or enones resulted in the synthesis of polyfunctional amides in high yields. The C-13 NMR characterization of these new compounds is presented.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Daiki Kato, Tomoya Murase, Jalindar Talode, Haruki Nagae, Hayato Tsurugi, Masahiko Seki, Kazushi Mashima
Summary: This study demonstrates the selective synthesis of multifunctionalized ketones using copper salts and aryl Grignard reagents. The method shows good tolerance towards various functional groups and can be applied to the synthesis of important synthetic intermediates.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Darryl F. Nater, Christoph J. Kaul, Lukas Laetsch, Hayato Tsurugi, Kazushi Mashima, Christophe Coperet
Summary: Tailored molybdenum (VI)-oxo complexes can catalyze olefin metathesis reaction under specific conditions, and the structural, spectroscopic and electronic characteristics of the catalyst precursor have an influence on the initiation and catalytic efficiency of the final product.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Koichi Shinohara, Hayato Tsurugi, Kazushi Mashima
Summary: In this study, a novel lanthanum amide complex was reported as an efficient catalyst for the N-methylation of N-alkylaniline derivatives with CO2 in the presence of PhSiH3. Experimental and computational investigations revealed the crucial role of multiple noncovalent interactions in the reaction mechanism.
Article
Chemistry, Organic
Hayato Tsurugi, Minami Matsuno, Tomomi Kawakami, Kazushi Mashima
Summary: N,N'-Bis(trimethylsilyl)-1,4-dihydropyrazines can be used to synthesize alkylpyrazines by combining with aldehydes and tetra(n-butyl)ammonium fluoride. Various sources of alkyl substituents, such as aryl, heteroaryl, and alkyl aldehydes, can be utilized with good yields obtained from reactions with electron-rich aldehydes. DFT calculations clarified the overall reaction sequence, with the key steps being the activation of the N-trimethylsilyl moiety by fluoride and the subsequent C-C bond formation with aldehydes.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Kohei Nishi, Hayato Tsurugi, Kazushi Mashima
Summary: Chromium-catalyzed olefination of aryl aldehydes with haloforms using 2,3,5,6-tetramethyl-N,N'-bis(trimethylsilyl)-1,4-dihydropyrazine (1a) as an organic reducing agent leads to trans-selective formation of beta-halostyrene derivatives. This reaction eliminates the need for metal powders such as zinc and manganese as reductants, reducing metal-based reaction waste.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Yohei Ueda, Hayato Tsurugi, Kazushi Mashima
Summary: Cobalt-catalyzed hydroalkynylation of alkynes, alkenes, and imines allows for the synthesis of internal alkynes with various functional groups adjacent to the carbon-carbon triple bond in an atom-economical manner. In addition, cross-coupling reactions using alkynylcobalt species generated in situ from terminal alkynes, haloalkynes, and metal acetylides selectively provide internal aryl and alkylalkynes.
Article
Chemistry, Physical
Kosuke Higashida, Valentin Smail, Haruki Nagae, Jean-Francois Carpentier, Kazushi Mashima
Summary: We successfully achieved nickel(0)-catalyzed asymmetric allylic alkylation (AAA) of beta-dicarbonyl compounds under ambient conditions by activating unstrained C-C bonds of 2-allylated 2-methylcyclohexane-1,3-dione derivatives. The reaction produced quaternary chiral compounds with high yield and enantioselectivity. The mechanism of the AAA reaction with the Ni(0)-(S)-tol-MeO-BIPHEP catalyst system was elucidated through control experiments and DFT calculations.
Review
Chemistry, Multidisciplinary
Takanori Iwasaki, Nobuaki Kambe
Summary: Carbon-fluorine bonds are stable but can be selectively transformed under appropriate conditions, making them useful synthetic methods in organic chemistry. This review focuses on C-C bond formation at monofluorinated sp(3)-hybridized carbons via C-F bond cleavage, including cross-coupling and multi-component coupling reactions. The mechanisms of C-F bond cleavage on sp(3)-hybridized carbon centers are categorized into three types: Lewis acids promoted F atom elimination, nucleophilic substitution with metal or carbon nucleophiles, and cleavage of C-F bonds via single electron transfer. Furthermore, the unique characteristics of alkyl fluorides compared to other (pseudo)halides as electrophilic coupling counterparts are discussed.
Article
Multidisciplinary Sciences
Takanori Iwasaki, Kazuki Tsuge, Naoki Naito, Kyoko Nozaki
Summary: This study reports an Ir catalyst for the selective hydrogenolysis of urea derivatives, achieving the transformation of less reactive carbonyl compounds in the presence of more reactive ones. The proposed catalyst showed tolerance to highly reactive carbonyl groups such as ester, amide, and carbamate, and exhibited high chemoselectivity towards urea. This research provides a new strategy for the chemical recycling of polyurea resins.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Kohei Nishi, Hayato Tsurugi, Kazushi Mashima
Summary: Chromium(III) trichloride combined with aryl/alkyl Grignard reagents showed high catalytic activity for the synthesis of syn-2-aryl/alkyl-1,2-dihydronaphthalen-1-ols through the ring-opening aryl/alkylation of 7-oxabenzonorbornadiene derivatives. The chromium catalyst allowed the use of unstable aryl Grignard reagents with esters and N-protecting groups. In situ formed diarylchromate(I) from tetraarylchromate(III) was identified as the active species in this catalytic reaction based on control experiments.
Article
Chemistry, Multidisciplinary
Haruki Nagae, Saki Matsushiro, Jun Okuda, Kazushi Mashima
Summary: We discovered that a cationic hetero tetranuclear complex with a calcium and three cobalt ions demonstrated high catalytic activity for the alternating copolymerization of propylene oxide (PO) and carbon dioxide (CO2). The tertiary anilinium salt [PhNMe2H][B(C6F5)(4)] was identified as the best additive to generate the cationic species and maintain polymer selectivity and carbonate linkage, even at 1.0 MPa CO2. Density functional theory calculations revealed that the reaction pathway mediated by the cationic complex is more favorable than that mediated by the neutral complex, with an energy difference of 1.0 kcal mol(-1). Additionally, we found that the exchange of flexible ligands between calcium and cobalt ions is crucial for the smooth proceeding of the alternating copolymerization.
Article
Chemistry, Physical
Kohei Nishi, Hayato Tsurugi, Kazushi Mashima
Summary: Chromium(III) trichloride in combination with aryl/alkyl Grignard reagents exhibited high catalytic activity for the ring-opening arylation reaction of 7-oxabenzonorbornadiene derivatives, producing syn-2-aryl/alkyl-1,2-dihydronaphthalen-1-ols in high yields. The superior catalytic activity of the chromium catalyst allowed the use of unstable aryl Grignard reagents. Control experiments suggested that the in situ formed diarylchromate(I) served as the active species in the catalytic reaction.
Article
Chemistry, Physical
Kosuke Higashida, Valentin Smail, Haruki Nagae, Jean-Francois Carpentier, Kazushi Mashima
Summary: We achieved a nickel(0)-catalyzed asymmetric allylic alkylation reaction of beta-dicarbonyl compounds under ambient conditions, resulting in high yields of quaternary chiral compounds with high enantioselectivity.
Article
Chemistry, Physical
Takanori Iwasaki, Wataru Ishiga, Shrinwantu Pal, Kyoko Nozaki, Nobuaki Kambe
Summary: This study reports the mechanistic investigation of the Rh-catalyzed cross-coupling reaction between vinylic ethers and aryl Grignard reagents. The presence of olefinic ligands significantly affects the catalytic activity of Rh precatalysts. Computational studies reveal that the reaction proceeds through Mg cation-assisted insertion/anti-beta-oxygen elimination, with the Mg countercation coordinating to the ethereal oxygen atom in the transition state.
