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Chemical Communications: Chem Comm

Jun Takaya, Ko Miyama, Chuan Zhu, Nobuharu Iwasawa
A PGeP-pincer palladium-catalyzed hydrocarboxylation of styrenes to obtain pharmaceutically important α-arylpropionic acid derivatives was achieved using a formate salt as both a reductant and a CO2 source. The reaction was also applicable to vinylsulfone and acrylates. Isotope labeling experiments demonstrated that a CO2-recycling mechanism is operative through generation and reaction of a benzylpalladium complex as a carbon nucleophile. This protocol has realized a mild and atom economical CO2-fixation reaction without the necessity of using strong metallic reductants...
March 23, 2017: Chemical Communications: Chem Comm
Qinglong Zhang, Yannan Zhu, Hongxing Jin, You Huang
A novel phosphine mediated sequential annulation process to construct functionalized aza-benzobicyclo[4.3.0] derivatives has been developed involving a one-pot sequential catalytic and stoichiometric process, which generates a series of benzobicyclo[4.3.0] compounds containing one quaternary center with up to 94% yield and 20 : 1 dr value. In this reaction, MBH carbonates act as 1,2,3-C3 synthons.
March 23, 2017: Chemical Communications: Chem Comm
Alankriti Bajpai, Matteo Lusi, Michael J Zaworotko
The aromatic core in dipyridyl linker ligands is found to impact the mode of 2-fold interpenetration in hybrid ultramicroporous materials formed by pillared square grid networks. An analysis of the crystal structures suggests that linker conformation and weak interactions between the linkers in adjacent networks might explain this phenomenon.
March 23, 2017: Chemical Communications: Chem Comm
Arthi Ravi, Syed Zahid Hassan, Ajithkumar N Vanikrishna, Kana M Sureshan
Triflates of myo-inositol undergo facile solvolysis in DMSO and DMF yielding SN2 products substituted with O-nucleophiles; DMF showed slower kinetics. Axial O-triflate undergoes faster substitution than equatorial O-triflate. By exploiting this difference in kinetics, solvent-tuning and sequence-controlled nucleophilysis, rapid synthesis of three azido-inositols of myo-configuration from myo-inositol itself has been achieved.
March 22, 2017: Chemical Communications: Chem Comm
Takuya Sagami, Yuhei O Tahara, Makoto Miyata, Hiroyuki Miyake, Satoshi Shinoda
Self-assembled europium(iii) complexes produced dispersed nanoparticles with diameters of about 4-8 nm, which exhibited long-lived luminescence in a 20 wt% EtOH-H2O solution. The complexes could sense weakly hydrated anions, such as perchlorate, by a change in luminescence intensity using an anion displacement method.
March 22, 2017: Chemical Communications: Chem Comm
Yasushi Imada, Yusuke Yamaguchi, Naoki Shida, Yohei Okada, Kazuhiro Chiba
Unactivated alkenes were previously found to be effective carbon nucleophiles for anodic cycloadditions in lithium perchlorate/nitromethane electrolyte solution. Herein, (7)Li NMR analysis and calorimetric studies clearly illustrate that the entropic effect is essential for these anodic cycloadditions, which has led to the successful screening of novel effective electrolytes.
March 22, 2017: Chemical Communications: Chem Comm
Deni Mance, Johan van der Zwan, Marjolein E Z Velthoen, Florian Meirer, Bert M Weckhuysen, Marc Baldus, Eelco T C Vogt
A combination of solid-state NMR techniques supported by EPR and SEM-EDX experiments was used to localize different carbon species (coke) in commercial fluid catalytic cracking catalysts. Aliphatic coke species formed during the catalytic process and aromatic coke species deposited directly from the feedstock respond differently to dynamic nuclear polarization signal enhancement in integral and crushed FCC particles, indicating that aromatic species are mostly concentrated on the outside of the catalyst particles, whereas aliphatic species are also located on the inside of the FCC particles...
March 22, 2017: Chemical Communications: Chem Comm
R Alex Mayo, David J Sullivan, Travis A P Fillion, Stefan W Kycia, Dmitriy V Soldatov, Kathryn E Preuss
An achiral organic molecule adopts a chiral conformation, crystallizing in two morphologies: a racemic form, stable <70 °C, and a homochiral form, stable ≥70 °C. Upon seeding, crystal-to-crystal phase transitions occur reversibly between the racemic and chiral forms. Liquid-to-solid chiral crystallization is observed >90% of the time from the melt.
March 22, 2017: Chemical Communications: Chem Comm
M Blümel, D Hack, L Ronkartz, C Vermeeren, D Enders
The development of a novel cooperative catalytic system for an amine-silver co-catalyzed Conia-ene reaction of alkyne-tethered C-H-acidic compounds is reported. By using a cost-effective silver salt and a small diamine for the 5-exo-dig-cyclization the cyclopentane products are obtained in very good yields. The enantioselectivity of the reaction could be controlled by exchanging the diamine co-catalyst with a cinchona-derived primary amine.
March 22, 2017: Chemical Communications: Chem Comm
Chen Zhang, Rahul S Patil, Tao Li, Charles L Barnes, Jerry L Atwood
The solvothermal synthesis of a metal-seamed hexameric nanocapsule from pyrogallol[4]arenes and magnesium is reported. The unique non-toxic and biocompatible nature of divalent magnesium cations in addition to the large inherent cavities make these nanocapsules promising for potential application in biomedicine. In addition, we show that these nanocapsules can form cocrystals with pyridine molecules through hydrogen bonding, which sheds light to cocrystallization of supramolecular nanocapsules with small pharmaceutics...
March 21, 2017: Chemical Communications: Chem Comm
Wei-Hui Fang, Lei Zhang, Jian Zhang
A series of binary cluster-based crystalline materials consisting of the same cationic polyoxotitanium cluster (PTC) and different anionic copper halide clusters (CuX) have been prepared. Interestingly, these complexes display analogous structure types to inorganic salts and present various light absorption properties.
March 21, 2017: Chemical Communications: Chem Comm
Shu-Hou Yang, Qi Sun, Hao Xiong, Shi-Yu Liu, Behrooz Moosavi, Wen-Chao Yang, Guang-Fu Yang
We report herein the structure-based design and application of a fluorogenic molecular probe (BChE-FP) specific to butyrylcholinesterase (BChE). This probe was rationally designed by mimicking the native substrate and optimized stepwise by manipulating the steric feature and the reactivity of the designed probe targeting the structural difference of the active pockets of BChE and AChE. The refined probe, BChE-FP, exhibits high specificity toward BChE compared to AChE, producing about 275-fold greater fluorescence enhancement upon the catalysis by BChE...
March 21, 2017: Chemical Communications: Chem Comm
Yu Su, Yoshihiro Tsujimoto, Akira Miura, Shinichiro Asai, Maxim Avdeev, Hiraku Ogino, Miho Ako, Alexei A Belik, Takatsugu Masuda, Tetsuo Uchikoshi, Kazunari Yamaura
A new square-planar zinc oxyhalide, Sr2ZnO2Cl2, was successfully synthesized using a high-pressure method. Absorption spectroscopy revealed an indirect band gap of 3.66 eV. Electronic structure calculations indicated a strong hybridization between Zn 3dx(2)-y(2) and O 2p orbitals, which is distinct from tetrahedrally coordinated ZnO.
March 21, 2017: Chemical Communications: Chem Comm
Aleix Comas-Vives, Kim Larmier, Christophe Copéret
The characterization of the active sites in heterogeneous catalysts is highly challenging and hinders the rational development and design of better catalysts. One approach to achieve this goal is Surface Organometallic Chemistry (SOMC), which allows generation of well-defined active sites characterized at the molecular level using spectroscopic methods. Due to many advances in the field and the increase of computational power, Computational Chemistry (CompChem) plays a key role in providing an atomistic understanding of these systems and the nature of the active sites...
March 21, 2017: Chemical Communications: Chem Comm
Daniel Mann, Stefanie Voogt, Ryan van Zandvoort, Helmut Keul, Martin Möller, Marcel Verheijen, Daniel Nascimento-Duplat, Man Xu, H Paul Urbach, Aurèle J L Adam, Pascal Buskens
Protecting groups are commonly applied in multi-step molecular syntheses to protect one or multiple functional groups from reacting. After the reaction, they are removed from the molecule. In full analogy to this concept, we report the practical and scalable colloidal synthesis of Au semishells using polyphenylsiloxane protecting patches to prevent part of the surface of polystyrene nanoparticles from being covered with Au. After Au deposition, the patches are removed yielding Au semishells. We anticipate that this strategy can be extended to the synthesis of other types of non-centrosymmetric nanoparticles...
March 21, 2017: Chemical Communications: Chem Comm
L Sánchez-García, N Serna, M Mattanovich, P Cazzanelli, A Sánchez-Chardi, O Conchillo-Solé, F Cortés, X Daura, U Unzueta, R Mangues, A Villaverde, E Vázquez
We demonstrate here that the genetic incorporation of the fusogenic peptide HA2 into a CXCR4-targeted protein nanoparticle dramatically reduces the specificity of the interaction between nanoparticles and cell receptors, a factor to be considered when designing tumor-homing drug vehicles displaying endosomal-escape agents. The loss of specificity is concomitant with enhanced cell penetrability.
March 21, 2017: Chemical Communications: Chem Comm
Madala Hari Babu, Gadi Ranjith Kumar, Ruchir Kant, Maddi Sridhar Reddy
Addition of arylboronic acids to directing group tethered acetylenes in a regio and stereoselective manner using an inexpensive catalytic system is achieved for the first time to access highly sought after allyl/homoallyl alcohol/amine units. The apparent vinylnickel intermediate was successfully trapped by the Michael electrophiles to get defined tri- and tetra-substituted olefins. An interesting selectivity switch was observed with internal alkynes.
March 20, 2017: Chemical Communications: Chem Comm
Xueling Shan, Takuya Yamauchi, Yojiro Yamamoto, Saroh Niyomdecha, Kengo Ishiki, Dung Q Le, Hiroshi Shiigi, Tsutomu Nagaoka
Specific identification of enterohemorrhagic Escherichia coli was achieved using microspheres coated with overoxidized polypyrrole. The microspheres are well dispersed in aqueous media, and they specifically, spontaneously, and efficiently bind E. coli O157:H7 through surface area effects. In addition, we found that light-scattering by a single microsphere depended linearly on the number of bound cells.
March 20, 2017: Chemical Communications: Chem Comm
Cheng Hu, Yang Yu, Jiangyun Wang
While many artificial metalloenzymes have been reported, and are proposed to be highly promising for energy, environmental and medical applications, few could match the turnover rate (TOR) and turnover number (TON) of natural enzymes. Since electron transfer is oftentimes the rate-determining step, optimizing the electron transfer efficiency is an effective approach to significantly enhance artificial enzymes' activity. In this article, we review the recent progress in improving artificial metalloenzymes' activity by optimizing electron transfer...
March 20, 2017: Chemical Communications: Chem Comm
Siying Che, Rina Dao, Weidong Zhang, Xiaoyu Lv, Haoran Li, Congmin Wang
A novel anion-functionalized fluorescent ionic liquid was designed and prepared, which was capable of capturing sulphur dioxide with high capacity and could also be used as a good colorimetric and fluorescent SO2 sensor. Compared to conventional fluorescent sensors, this fluorescent ionic liquid did not undergo aggregation-caused quenching or aggregation-induced emission, and the fluorescence was quenched when exposed to SO2, and the fluorescence would quench when exposed to SO2. The experimental absorption, spectroscopic investigation, and quantum chemical calculations indicated that the quenching of the fluorescence originated from SO2 physical absorption, not chemical absorption...
March 20, 2017: Chemical Communications: Chem Comm
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