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Full-Text Articles in Chemistry
Fluorination Of Aromatic Ring Systems, Stephen G. Dimagno
Fluorination Of Aromatic Ring Systems, Stephen G. Dimagno
Chemistry Department: Faculty Publications
This disclosure relates to reagents and methods useful in the synthesis of aryl fluorides, for example, in the preparation of 18F labeled radiotracers. The reagents and methods provided herein may be used to access a broad range of compounds, including aromatic compounds, heteroaromatic compounds, amino acids, nucleotides, and synthetic compounds.
Probing The Bifunctional Catalytic Activity Of Ceria Nanorods Towards The Cyanosilylation Reaction, Gonghua Wang, Lu Wang, Xiang Fei, Yunyun Zhou, Renat F. Sabirianov, Wai-Ning Mei, Chin Li Cheung
Probing The Bifunctional Catalytic Activity Of Ceria Nanorods Towards The Cyanosilylation Reaction, Gonghua Wang, Lu Wang, Xiang Fei, Yunyun Zhou, Renat F. Sabirianov, Wai-Ning Mei, Chin Li Cheung
Chemistry Department: Faculty Publications
Ceria nanorods were demonstrated to be an active, bifunctional catalyst for the cyanosilylation of aldehydes. The catalytic activity of ceria was shown to be positively correlated with a decrease in the coordination numbers of neighbouring oxygen atoms around cerium atoms in the catalyst. Chemisorption and density functional theory studies suggested that the coordinatively unsaturated cerium sites exposed by the surface oxygen vacancy defects functioned as Lewis acid sites and the neighbouring oxygen atoms behaved as Lewis base sites in the catalytic cycle.
An Expanded Genetic Code In Mammalian Cells With A Functional Quadruplet Codon, Wei Niu, Peter G. Schultz, Jiantao Guo
An Expanded Genetic Code In Mammalian Cells With A Functional Quadruplet Codon, Wei Niu, Peter G. Schultz, Jiantao Guo
Chemistry Department: Faculty Publications
We have utilized in vitro evolution to identify tRNA variants with significantly enhanced activity for the incorporation of unnatural amino acids into proteins in response to a quadruplet codon in both bacterial and mammalian cells. This approach will facilitate the creation of an optimized and standardized system for the genetic incorporation of unnatural amino acids using quadruplet codons, which will allow the biosynthesis of biopolymers that contain multiple unnatural building blocks.
Iodonium Cyclophanes For Secure Arene Functionalization, Stephen Dimagno
Iodonium Cyclophanes For Secure Arene Functionalization, Stephen Dimagno
Chemistry Department: Faculty Publications
This disclosure relates to compounds, reagents, and methods useful in the synthesis of aryl fluorides, for example, in the preparation of 18F labeled radiotracers. For example, this disclosure provides universal “locked” aryl substituents that result in StereoElectronic Control of Unidirectional Reductive Elimination (SECURE) from diaryliodonium salts. The reagents and methods provided herein may be used to access a broad range of compounds, including aromatic compounds, heteroaromatic compounds, amino acids, nucleotides, and synthetic compounds.
Probing The Bifunctional Catalytic Activity Of Ceria Nanorods Towards The Cyanosilylation Reaction, Gonghua Wang, Lu Wang, Xiang Fei, Yunyun Zhou, Renat F. Sabirianov, Wai Ning Mei, Chin Li Cheung
Probing The Bifunctional Catalytic Activity Of Ceria Nanorods Towards The Cyanosilylation Reaction, Gonghua Wang, Lu Wang, Xiang Fei, Yunyun Zhou, Renat F. Sabirianov, Wai Ning Mei, Chin Li Cheung
Chemistry Department: Faculty Publications
Ceria nanorods were demonstrated to be an active, bifunctional catalyst for the cyanosilylation of aldehydes. The catalytic activity of ceria was shown to be positively correlated with a decrease in the coordination numbers of neighbouring oxygen atoms around cerium atoms in the catalyst. Chemisorption and density functional theory studies suggested that the coordinatively unsaturated cerium sites exposed by the surface oxygen vacancy defects functioned as Lewis acid sites and the neighbouring oxygen atoms behaved as Lewis base sites in the catalytic cycle.
Single Transcriptional And Translational Preq1 Riboswitches Adopt Similar Pre-Folded Ensembles That Follow Distinct Folding Pathways Into The Same Ligand-Bound Structure, Krishna C. Suddala, Arlie J. Rinaldi, Jun Feng, Anthony M. Mustoe, Catherine D. Eichhorn, Joseph A. Liberman, Joseph E. Wedekind, Hashim M. Al-Hashimi, Charles L. Brooks Iii, Nils G. Walter
Single Transcriptional And Translational Preq1 Riboswitches Adopt Similar Pre-Folded Ensembles That Follow Distinct Folding Pathways Into The Same Ligand-Bound Structure, Krishna C. Suddala, Arlie J. Rinaldi, Jun Feng, Anthony M. Mustoe, Catherine D. Eichhorn, Joseph A. Liberman, Joseph E. Wedekind, Hashim M. Al-Hashimi, Charles L. Brooks Iii, Nils G. Walter
Chemistry Department: Faculty Publications
Riboswitches are structural elements in the 50 untranslated regions of many bacterial messenger RNAs that regulate gene expression in response to changing metabolite concentrations by inhibition of either transcription or translation initiation. The preQ1 (7-aminomethyl-7-deazaguanine) riboswitch family comprises some of the smallest metabolite sensing RNAs found in nature. Once ligand-bound, the transcriptional Bacillus subtilis and translational Thermoanaerobacter tengcongensis preQ1 riboswitch aptamers are structurally similar RNA pseudoknots; yet, prior structural studies have characterized their ligand-free conformations as largely unfolded and folded, respectively. In contrast, through single molecule observation, we now show that, at nearphysiological Mg2+ concentration and pH, …
High-Performance Flexible Solid-State Supercapacitors Based On Mno2-Decorated Nanocarbon Electrodes, Yang Gao, Yun Shen Zhou, Min Qian, Hao Ming Li, Jody G. Redepenning, Li Sha Fan, Xiang Nan He, Wei Xiong, Masoud Majhouri-Samani, Lan Jiang, Yongfeng Lu
High-Performance Flexible Solid-State Supercapacitors Based On Mno2-Decorated Nanocarbon Electrodes, Yang Gao, Yun Shen Zhou, Min Qian, Hao Ming Li, Jody G. Redepenning, Li Sha Fan, Xiang Nan He, Wei Xiong, Masoud Majhouri-Samani, Lan Jiang, Yongfeng Lu
Chemistry Department: Faculty Publications
Flexible energy storage units are highly desired to meet the ever-increasing demands for flexible electronics. In this paper, highly flexible solid-state supercapacitors are fabricated using MnO2-decorated nanocarbon electrodes and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide–poly(vinylidene fluoride)- hexafluoropropylene ([EMIM][NTf2]–PVdF(HFP)) gel electrolytes. The flexible electrodes are prepared by electrodepositing MnO2 onto the carbon nanotube/carbon nanoonion (CNT/CNO) films. CNT/CNO films have a large surface area for MnO2 deposition and work as mechanical supports with high flexibility and light weight. CNOs act as spacers to separate CNTs, introducing mesopores inside the CNT/CNO films for preventing pore blocking during MnO2 deposition. The supercapacitor exhibits …
A Facile, Low-Cost Route For The Preparation Of Calcined Porous Calcite And Dolomite And Their Application As Heterogeneous Catalysts In Biodiesel Production, Rui Wang, Hu Li, Fei Chang, Jiafeng Luo, Milford A. Hanna, Daoyang Tan, Deyu Hu, Yuping Zhang, Baoan Song, Song Yang
A Facile, Low-Cost Route For The Preparation Of Calcined Porous Calcite And Dolomite And Their Application As Heterogeneous Catalysts In Biodiesel Production, Rui Wang, Hu Li, Fei Chang, Jiafeng Luo, Milford A. Hanna, Daoyang Tan, Deyu Hu, Yuping Zhang, Baoan Song, Song Yang
Chemistry Department: Faculty Publications
Despite their potential for biodiesel synthesis, directly calcined minerals rich in magnesium/calcium carbonates are used at the expense of large amounts of the catalyst, high alcohol loading, long processing times, and severe conditions. We report a facile and low-cost route for preparing calcined porous calcite (CPC) and dolomite (CPD) via simple thermal decomposition of the reaction mixtures of natural calcite and dolomite with stearic acid. CPC and CPD, both of which have porous structures, were compared with previously reported catalysts and examined as promising heterogeneous base catalysts under mild conditions. A 40% increase in conversion through CPC and CDC was …
Re2o7-Catalyzed Reaction Of Hemiacetals And Aldehydes With O-, S-, And C-Nucleophiles, Wantanee Sittiwong, Michael W. Richardson, Charles E. Schiaffo, Thomas J. Fisher, Patrick H. Dussault
Re2o7-Catalyzed Reaction Of Hemiacetals And Aldehydes With O-, S-, And C-Nucleophiles, Wantanee Sittiwong, Michael W. Richardson, Charles E. Schiaffo, Thomas J. Fisher, Patrick H. Dussault
Chemistry Department: Faculty Publications
Re(VII) oxides catalyze the acetalization, monoperoxyacetalization, monothioacetalization and allylation of hemiacetals. The reactions, which take place under mild conditions and at low catalyst loadings, can be conducted using hemiacetals, the corresponding O-silyl ethers, and, in some cases, the acetal dimers. Aldehydes react under similar conditions to furnish good yields of dithioacetals. Reactions of hemiacetals with nitrogen nucleophiles are unsuccessful. 1,2-Dioxolan-3-ols (peroxyhemiacetals) undergo Re(VII)-promoted etherification but not allylation. Hydroperoxyacetals (1-alkoxyhydroperoxides) undergo selective exchange of the alkoxide group in the presence of either Re2O7 or a Brønsted acid.
Stress Reduction For Pillar Filled Structures, Rebecca J. Nikolic, Adam Conway, Qinghui Shao, Lars Voss, Chin Li Cheung, Mushtaq A. Dar
Stress Reduction For Pillar Filled Structures, Rebecca J. Nikolic, Adam Conway, Qinghui Shao, Lars Voss, Chin Li Cheung, Mushtaq A. Dar
Chemistry Department: Faculty Publications
According to one embodiment, an apparatus for detecting neutrons includes an array of pillars, wherein each of the pillars comprises a rounded cross sectional shape where the cross section is taken perpendicular to a longitudinal axis of the respective pillar, a cavity region between each of the pillars, and a neutron sensitive material located in each cavity region.
Porous Polymer Coatings As Substrates For The Formation Of High-Fidelity Micropatterns By Quill-Like Pens, Michael Hirtz, Marcus Lyon, Wenqian Feng, Andrea E. Holmes, Harald Fuchs, Pavel A. Levkin
Porous Polymer Coatings As Substrates For The Formation Of High-Fidelity Micropatterns By Quill-Like Pens, Michael Hirtz, Marcus Lyon, Wenqian Feng, Andrea E. Holmes, Harald Fuchs, Pavel A. Levkin
Chemistry Department: Faculty Publications
We explored the potentials of microarray printing using quill-like microcantilevers onto solid supports that are typically used in microspot printing, including paper, polymeric nitrocellulose and nylon membranes. We compared these membranes with a novel porous poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) support (HEMA) with narrow pore size distribution in the 150 nm range, which demonstrated advantages in pattern definition, spot homogeneity, and consistent spot delivery of different dyes (phloxine B and bromophenol blue) with diameters of several micrometres. The bromophenol blue arrays on HEMA support were used to detect the presence of bovine serum albumin (BSA). In the presence of BSA, …