Article
Chemistry, Physical
Melek Canbulat Ozdemir, Ebru Aktan, Onur Sahin
Summary: This study synthesized and characterized tunable protic pyrazolium salts with different substituents, and observed the association of like-charged ions in these salts. The effect of substituents on this association was investigated using X-ray structure analysis and theoretical calculations.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Chemistry, Multidisciplinary
Christian L. L. Jankovic, Kyle C. C. McIntosh, Verner A. A. Lofstrand, F. G. West
Summary: Mild fluoride-mediated desilylative conditions generate 1,2-cyclohexadienes, which undergo efficient intramolecular [2+2] trapping to form tricyclic alkylidene cyclobutanes with complete diastereoselectivity for the cis-fused products. These cyclohexadienes can be trapped by pendent styrenes or electron-deficient olefins, and 14 substrates have been disclosed. The reactions achieve yields up to 91% at ambient temperature using only cesium fluoride and the necessary precursors are easily accessible from substituted 2-bromocyclohexenones.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Melissa Ramirez, Dennis Svatunek, Fang Liu, Neil K. Garg, Kendall N. Houk
Summary: The Diels-Alder reactions of furans and pyrroles with 1,2-cyclohexadiene and oxa- and azaheterocyclic analogs exhibit endo selectivity, which is determined by the interaction of molecular orbitals and electrostatic effects. This selectivity, based on stabilizing interactions, is expected to lead to the increased use of strained cyclic allenes in chemical synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Danning Zheng, Fang Liu, Tengfei Wang, Zhengkun Zhang, Hans agren, Jinglai Zhang, Marten S. G. Ahlquist, Li Wang
Summary: Dual-ionic pyrazolium salts were synthesized and found to efficiently catalyze the coupling reaction of CO2 with epichlorohydrin. The addition of water greatly improved the product yield and the formation rate of the carbonate. The mechanism of water's dual role in affecting CO2 mass transfer and triggering proton transfer for efficient CO2 conversion was proposed and confirmed by spectroscopy results.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Xin Ji, Ziyang Li, Jinfeng Zhang, Yicheng Zhang, Ling-Guo Meng
Summary: In this study, a DMAP-catalyzed [4+2] annulation of alpha-substituted allenoates with arylazosulfones is described, leading to the synthesis of tetrahydropyridazine derivatives in high yields. The reaction exhibits mild conditions and excellent tolerance towards various functional groups. Furthermore, the resulting products can be easily converted into pyridazin-3-one derivatives in the presence of DDQ.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Lukas Koerner, Luong Phong Ho, Ralph Puchta, Amnon Stanger, Matthias Tamm
Summary: The synthesis of a new diaminoacetylene compound and its reaction to form a cyclic bent allene compound were successfully achieved. Furthermore, a compound containing a tetraaminocyclobutadiene dication was obtained and extensively studied.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Yuling Lu, Xianxian Duan, Xia Chen, Meng Yao, Chunmei Chen, Hucheng Zhu, Zengwei Luo, Yonghui Zhang
Summary: The mild intramolecular tetradehydro-Diels-Alder (TDDA) reaction of aryldiyne compounds with linear naphthalenes is presented, exhibiting good functional group tolerance. The reaction is easy to operate and suitable for multigram-scale synthesis. From the preliminary work, it was found that the mild conditions may be the key for obtaining completely linear products in the reactions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Aleksandra A. Ageeva, Roman S. Lukyanov, Sofia O. Martyanova, Ilya M. Magin, Alexander I. Kruppa, Nikolay E. Polyakov, Victor F. Plyusnin, Alexander B. Doktorov, Tatyana V. Leshina
Summary: This study investigates the photoinduced intramolecular and intermolecular processes of short peptides Lysine-Tryptophan-Lysine (Lys-{L/D-Trp}-Lys) and Lys-Trp-Lys with an acetate counter-ion. The reactivity of L- and D-amino acids has been a focus in various specialties, particularly in relation to Alzheimer's disease. Through NMR, CIDNP, and fluorescence techniques, the influence of tryptophan optical configuration on fluorescence quantum yields, quenching rates, and photocleavage products was observed. Results show that the L-isomer has a higher efficiency in quenching the Trp excited state compared to the D-analog, indicating an electron transfer mechanism.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Organic
Cunzhi Chen, Shuyan Fang, Mingwu Yu, Jiaxi Xu, Zhanhui Yang
Summary: In this study, tetrasubstituted thiophenes were produced in a redox-neutral manner through site-specific and regio-selective transannulation of Allenoates with 1,2,3-thiadiazoles in the presence of catalytic Rh(i)/bisphosphine. The 1,2,3-thiadiazoles act as masked 1,3-dipoles with nucleophilic sulfur and electrophilic carbon termini.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Kazutaka Kanayama, Ayumi Sawada, Katsushi Suda, Tetsuaki Fujihara
Summary: Regioselective sila-acylation and silaformylation of 1,3-dienes using a copper catalyst and silylborane as a silyl source resulted in the synthesis of β,γ-unsaturated ketones and aldehydes with a (dimethylphenyl-silyl)methyl moiety at the α-position, respectively.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Wen-Xuan Lin, Zhuolin Pei, Cunxi Gong, Huilin Mo, Kai Yang, Ling-Bo Qu, Donghui Wei, Jin-Shuai Song, Shi-Jun Li, Yu Lan
Summary: In the study of the mechanism of phosphine-catalyzed [8+2] cycloaddition, it was found that electrophilicity plays a role in hindering nucleophilic attack but is not predictive of priority.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Applied
Yi Liu, Yuhang Hu, Jiarong Zhang, Jingsheng Zhou, Zhengkun Zhang, Jinglai Zhang, Li Wang
Summary: This study grafted a series of amino-functionalized pyrazolium ionic liquids onto SBA-15 and found that SBA-15-APMPzBr(20) exhibited good catalytic activity and recyclability. Experimental results indicated that the hydroxyl groups in SBA-15 promoted the ring-opening of substrate.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Biochemistry & Molecular Biology
Sylwia Zieba, Agata Piotrowska, Adam Mizera, Pawel Lawniczak, Karolina H. Markiewicz, Andrzej Gzella, Alina T. Dubis, Andrzej Lapinski
Summary: The study analyzed the increase in conductivity with temperature in 1H-pyrazol-2-ium 2,6-dicarboxybenzoate monohydrate and discussed the influence of water mobility. The electric properties of the salt were studied using impedance spectroscopy method, and various analytical techniques were used to analyze hydrogen bond interactions and the role of water molecules in forming structural defects.
Article
Chemistry, Organic
Swati Jain, Ruchi Anmol, Ruchi Sharma, Tarak Karmakar, M. Ramu Yadav
Summary: We have developed an efficient Cu/N,N-bidentate imine ligand catalytic system for C(sp(3))-C(sp) coupling, which can synthesize internal alkynes, di/trisubstituted allenes, and strained bridged cyclic lactams in moderate to excellent yields from readily available alkyl(benzyl) bromides. Density Functional Theory (DFT) assisted mechanistic study and control experiments support the involvement of bialkynylated copper species in the reaction, which undergoes single electron transfer (SET) with alkyl halides to generate radical intermediates. The N,N-bidentate imine ligand plays a crucial role in stabilizing the intermediate copper complex and facilitating product formation.
Article
Polymer Science
Le Zhou, Alexandria Triozzi, Marxa Figueiredo, Todd Emrick
Summary: This study describes the attachment of fluorinated alkyl groups to choline phosphate (CP) moieties, resulting in the production of a new set of fluorinated polymers and copolymers containing CP and phosphorylcholine (PC) zwitterions. These novel polymeric amphiphiles, combining fluorinated hydrocarbons and zwitterions, have potential applications in fluid interfaces, coatings, cell culture, and magnetic resonance imaging.
