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1. Stereoselective Total Synthesis of (−)-(2S,4R)-3′-Methoxyl Citreochlorol: Preparation and Use of New Proline-Based Auxiliary for Asymmetric Acetate Aldol Reaction

Author:
Sunnapu, Ranganayakulu; Banoth, Saikumar Naik; R. S., Reyno; Thomas, Aleena; Venugopal, Navyasree; Rajendar, Goreti
Source:
Journal of organic chemistry 2020 v.85 no.6 pp. 4103-4113
ISSN:
1520-6904
Subject:
acetates,   etc   ; methylene chloride; moieties; optical isomerism; stereoselectivity;     Show all 5 Subjects
Abstract:
... The first stereoselective total synthesis of (−)-(2S,4R)-3′-methoxy citreochlorol and (−)-(2S,4S)-3′-methoxy citreochlorol is demonstrated. A proline-based imidazolidinone was synthesized and used as chiral auxiliary for asymmetric acetate aldol reaction to generate initial chirality in the targeted molecule. Geminal dichloromethane functionality was introduced by the addition of in situ generated ...
DOI:
10.1021/acs.joc.9b03227

2. Butyric acid as sole product from xylose fermentation by a non-solventogenic Clostridium beijerinckii strain under controlled pH and nutritional conditions

Author:
Fonseca, Bruna Constante; Bortolucci, Jonatã; da Silva, Thalita Marques; dos Passos, Vinícius Fabiano; de Gouvêa, Paula Fagundes; Dinamarco, Taísa Magnani; Reginatto, Valeria
Source:
Bioresource technology reports 2020 v.10 pp. 100426
ISSN:
2589-014X
Subject:
acetate kinase; acetates,   etc   ; Clostridium beijerinckii; butyric acid; carbon nitrogen ratio; fermentation; genes; lignocellulose; pH; xylose;     Show all 10 Subjects
Abstract:
... Fermentative processes allow butyric acid to be produced from renewable substrates, which makes this compound commercially attractive. We have employed the non-solventogenic C. beijerinckii strain Br21 to obtain butyric acid from xylose under different nutritional conditions and controlled pH. Reinforced Clostridium Medium (RCM), which has the lowest C/N ratio, provided the highest butyrate/acetat ...
DOI:
10.1016/j.biteb.2020.100426

3. Liquid chromatography–electrospray ionization-tandem mass spectrometry for the determination of short-chain chlorinated paraffins in mixed plastic wastes

Author:
Matsukami, Hidenori; Takemori, Hiroaki; Takasuga, Takumi; Kuramochi, Hidetoshi; Kajiwara, Natsuko
Source:
Chemosphere 2020 v.244 pp. 125531
ISSN:
0045-6535
Subject:
acetates; ammonium acetate,   etc   ; alkanes; gas chromatography; liquid chromatography; methanol; persistent organic pollutants; tandem mass spectrometry; wastes;     Show all 9 Subjects
Abstract:
... Wastes containing short-chain chlorinated paraffins (SCCPs) at concentrations above the Basel Convention low persistent organic pollutant content (LPC) values must be destroyed or irreversibly transformed in an environmentally-sound manner. Here, we developed a novel liquid chromatography–electrospray ionization-tandem mass spectrometry (LC–ESI-MSMS) method for determining the concentrations of SC ...
DOI:
10.1016/j.chemosphere.2019.125531

4. Regulated Crystallization of Efficient and Stable Tin-Based Perovskite Solar Cells via a Self-Sealing Polymer

Author:
Liu, Gengling; Liu, Cong; Lin, Zhuojia; Yang, Jia; Huang, Zengqi; Tan, Licheng; Chen, Yiwang
Source:
ACS applied materials & interfaces 2020 v.12 no.12 pp. 14049-14056
ISSN:
1944-8252
Subject:
acetates; ethylene-vinyl acetate,   etc   ; coatings; crystallization; humidity; oxygen; solar cells; tin;     Show all 8 Subjects
Abstract:
... Tin-based perovskite solar cells (PVSCs) have emerged as the most promising lead-free perovskite materials owing to their superior optoelectronic properties. However, the deficiency of accurate control of the tin-based perovskite crystallization process increases the possibility of unexpected perovskite film morphology and defects, resulting in inferior power conversion efficiency (PCE). Meanwhile ...
DOI:
10.1021/acsami.0c01311

5. Ion Mobility and Surface Collisions: Submicrometer Capillaries Can Produce Native-like Protein Complexes

Author:
Panczyk, Erin M.; Gilbert, Joshua D.; Jagdale, Gargi S.; Stiving, Alyssa Q.; Baker, Lane A.; Wysocki, Vicki H.
Source:
Analytical chemistry 2020 v.92 no.3 pp. 2460-2467
ISSN:
1520-6882
Subject:
acetates; ammonium acetate,   etc   ; C-reactive protein; activation energy; concanavalin A; dissociation; ionization; mass spectrometry; spectrometers; streptavidin;     Show all 10 Subjects
Abstract:
... The use of submicrometer capillaries for nanoelectrospray ionization of native proteins and protein complexes effectively reduces the number of nonspecific salt adducts to biological molecules, therefore increasing the apparent resolution of a mass spectrometer without any further instrument modifications or increased ion activation. However, the increased interaction between proteins and the surf ...
DOI:
10.1021/acs.analchem.9b03666
PubMed:
31909984
PubMed Central:
PMC7203676

6. Cascade cyclization and acyl migration of propargylic esters with isocyanides: rapid access to substituted furans

Author:
Hu, Jie; Fei, Youwen; Zhao, Hongbin; Wang, Zhishuang; Li, Chunju; Li, Jian
Source:
Chemical communications 2019 v.55 no.58 pp. 8394-8397
ISSN:
1364-548X
Subject:
acetates,   etc   ; cyclization reactions; furans;     Show all 3 Subjects
Abstract:
... A novel rearrangement of ester-activated propargylic acetate with isocyanide has been disclosed. This protocol enables a quick synthesis of polysubstituted furan derivatives. The reaction outcome also reveals that the ester group is employed for the construction of a furan ring and an acyl migration is observed. ...
DOI:
10.1039/c9cc03550h

7. Efficient access to chiral dihydrobenzoxazinones via Rh-catalyzed hydrogenation

Author:
Chen, Ziyi; Yin, Xuguang; Dong, Xiu-Qin; Zhang, Xumu
Source:
RSC advances 2019 v.9 no.27 pp. 15466-15469
ISSN:
2046-2069
Subject:
acetate esters,   etc   ; hydrogenation;     Show all 2 Subject
Abstract:
... Rh/(S)-DTBM-SegPhos-catalyzed asymmetric hydrogenation of prochiral (Z)-2-(2-oxo-2H-benzo[b][1,4]oxazin-3(4H)-ylidene)acetate esters was successfully developed. A series of chiral dihydrobenzoxazinones were prepared through this efficient methodology with good to excellent results (up to >99% conversion, 93% yield and >99% ee), which are important motifs in the biologically active molecules. ...
DOI:
10.1039/c9ra02694k

8. Experimental and Theoretical Comparison of Addition–Fragmentation Pathways of Diseleno- and Dithiocarbamate RAFT Agents

Author:
Matioszek, Dimitri; Mazières, Stéphane; Brusylovets, Oleksii; Lin, Ching Yeh; Coote, Michelle L.; Destarac, Mathias; Harrisson, Simon
Source:
Macromolecules 2019 v.52 no.9 pp. 3376-3386
ISSN:
1520-5835
Subject:
vinyl acetate,   etc   ; polymerization; sulfur;     Show all 3 Subjects
Abstract:
... Theoretical studies suggest that identically substituted dithio- and diselenocarbamate reversible addition–fragmentation chain transfer (RAFT) agents will have similar reactivity but that diselenocarbamate RAFT agents are more likely to undergo intermediate radical termination. These results are supported by an experimental study of polymerizations of vinyl acetate mediated by Se-cyanomethyl N,N-d ...
DOI:
10.1021/acs.macromol.9b00214

9. The conformational stability of terminal helices of [formula omitted]-repressor protein in aqueous dodine and choline-O-sulfate solutions

Author:
Paul, Srijita; Paul, Sandip
Source:
International journal of biological macromolecules 2020 v.154 pp. 1332-1346
ISSN:
0141-8130
Subject:
acetates,   etc   ; denaturation; dodine; ions; molecular dynamics; simulation models;     Show all 6 Subjects
Abstract:
... In this article, we have ventured into the denaturation of fast folding λ6-85-repressor protein at a millimolar concentration of dodine and henceforth, evaluated the candidature of choline-O-sulfate as a protecting osmolyte against it, employing classical molecular dynamics simulations. Our simulation results show that, the terminal helices of λ-repressor protein get unfolded in presence of ∼15 mM ...
DOI:
10.1016/j.ijbiomac.2019.11.013

10. Use of fluorescent probes in supporting functional group analysis resulting from polymer ageing

Author:
Hervé, Baptiste; Rapp, Géraldine; Bussiere, Pierre-Olivier; Gardette, Jean-Luc; Therias, Sandrine
Source:
Polymer degradation and stability 2020 v.177 pp. 109167
ISSN:
0141-3910
Subject:
acetates,   etc   ; alcohols; fluorescent dyes; moieties; oxygen; photooxidation; polyesters; polyethylene; polymethylmethacrylate;     Show all 9 Subjects
Abstract:
... Based on the determination of the solvatochromic parameters of a series of polymers with various functional groups containing oxygen atoms, a method was proposed which allowed for discriminating the oxidation products formed by exposure of polymers to photo- and/or thermo-ageing. The polymers used to determine the solvatochromic parameters contained polar groups such as chain-pendant ester (EVA, P ...
DOI:
10.1016/j.polymdegradstab.2020.109167

11. Evolution of the key odorants and aroma profiles in traditional Laowuzeng baijiu during its one-year ageing

Author:
Zhu, Lin; Wang, Xinlei; Song, Xuebo; Zheng, Fuping; Li, Hehe; Chen, Feng; Zhang, Yuhang; Zhang, Fuyan
Source:
Food chemistry 2020 v.310 pp. 125898
ISSN:
0308-8146
Subject:
acetates,   etc   ; 1-propanol; acids; aldehydes; honey; odor compounds; odors; vegetables;     Show all 8 Subjects
Abstract:
... Changes of key odorants and aroma profiles of Chinese Laowuzeng baijiu during its one-year ageing were determined by HS-SPME–AEDA and direct injection–AEDA (DI–AEDA). Ethyl hexanoate, (E,E)-2,4-decadienal, and 2-phenylethyl acetate showed the highest FD value (486) in all ageing stages. With regards to aroma profiles, fruity, floral, acidic, sweet/honey and cheesy aromas were enhanced during stora ...
DOI:
10.1016/j.foodchem.2019.125898

12. Synthesis of 3-S- and 3-Se-glycals by using R-S-S-R and R-Se-Se-R as the nucleophile precursors promoted by Hf(OTf)4 and the temperature-dependent formation of the above-mentioned 3-S- and 3-Se products

Author:
Chen, Peiran; Guo, Saisai; Zuo, Junfeng; Chu, Ruiji; He, Xu; Zhu, Guijiang
Source:
Tetrahedron letters 2020 v.61 no.12 pp. 151648
ISSN:
0040-4039
Subject:
acetates,   etc   ; Lewis bases; aromatic compounds; catalysts; chemical reactions; chemical structure;     Show all 6 Subjects
Abstract:
... By using Hf(OTf)₄ as the catalyst, under certain conditions, reaction of tri-O-acetyl-d-glucal and ((2R ,3S)-3-acetoxy-2,3-dihydrofuran-2-yl)methyl acetate with alkyl(aryl) bisulfide/alkyl(aryl) biselenide as nucleophile precursor leads to temperature-dependent formation of C-1-S/Se and C-3-S/Se product. A temperature-dependent profile of the yield of these two products is given. ...
DOI:
10.1016/j.tetlet.2020.151648

13. Synthesis of novel tetrols from syn-bisepoxide: Preparation of halogenated bicyclo[4.2.0] inositols

Author:
Karanfil, Abdullah; Şahin, Ertan; Kelebekli, Latif
Source:
Tetrahedron 2020 v.76 no.11 pp. 131000
ISSN:
0040-4020
Subject:
acetates,   etc   ; ammonia; chemical reactions; chemical structure; inositols; protons; spectroscopy; sulfates;     Show all 8 Subjects
Abstract:
... The synthesis of halogenated bicyclo[4.2.0] inositols (and/or tetrols) are described. The photooxygenation of trans-7,8-dibromobicyclo[4.2.0]octa-2,4-diene obtained using cyclooctatetraene as the starting molecule afforded the bicyclic endoperoxide. To obtain the halogenated bicyclo[4.2.0] inositols, the required key intermediate endoperoxide was rearranged quantitatively to the corresponding bise ...
DOI:
10.1016/j.tet.2020.131000

14. Improved Performance of CH₃NH₃PbI₃–ₓClₓ Resistive Switching Memory by Assembling 2D/3D Perovskite Heterostructures

Author:
Xia, Fei; Xu, Ying; Li, Bixin; Hui, Wei; Zhang, Shiyang; Zhu, Lin; Xia, Yingdong; Chen, Yonghua; Huang, Wei
Source:
ACS applied materials & interfaces 2020 v.12 no.13 pp. 15439-15445
ISSN:
1944-8252
Subject:
acetates,   etc   ; ambient temperature; computer hardware; information storage; iodides;     Show all 5 Subjects
Abstract:
... The rapidly growing demand for fast information storage and processing has driven the development of resistive random access memories (RRAMs). Recently, RRAMs based on organometal halide perovskite materials have been reported to have promising memory properties, which are essential for next-generation memory devices. In this study, a hybrid two-dimensional/three-dimensional (2D/3D) perovskite het ...
DOI:
10.1021/acsami.9b22732

15. Enhancing Grain Growth for Efficient Solution-Processed (Cu,Ag)₂ZnSn(S,Se)₄ Solar Cells Based on Acetate Precursor

Author:
Qi, Yafang; Liu, Yao; Kou, Dongxing; Zhou, Wenhui; Zhou, Zhengji; Tian, Qingwen; Yuan, Shengjie; Meng, Yuena; Wu, Sixin
Source:
ACS applied materials & interfaces 2020 v.12 no.12 pp. 14213-14223
ISSN:
1944-8252
Subject:
acetates,   etc   ; anions; crystal structure; crystallization; probability; solar cells;     Show all 6 Subjects
Abstract:
... Material crystallinity is the overriding factor in the determination of the photoelectric properties of absorber materials and the overall performance of the photovoltaic device. Nevertheless, in the Cu₂ZnSn(S,Se)₄ (CZTSSe) photovoltaic device, the bilayer or trilayer structure for the absorber has been broadly observed, which is generally harmful to the cell performance because the probability of ...
DOI:
10.1021/acsami.0c02629

16. Talauxins: Hybrid Phenalenone Dimers from Talaromyces stipitatus

Author:
Chaudhary, Nirmal K.; Crombie, Andrew; Vuong, Daniel; Lacey, Ernest; Piggott, Andrew M.; Karuso, Peter
Source:
Journal of natural products 2020 v.83 no.4 pp. 1051-1060
ISSN:
1520-6025
Subject:
acetates,   etc   ; Talaromyces stipitatus; amino acids; biosynthesis; density functional theory; fungi;     Show all 6 Subjects
Abstract:
... Cultivation and extraction of the fungus Talaromyces stipitatus led to the isolation of five new oxyphenalenone–amino acid hybrids, which were named talauxins E, Q, V, L, and I based on the corresponding one-letter amino acid codes, along with their putative biosynthetic precursor, duclauxin. The rapid reaction of duclauxin with amino acids to produce talauxins was demonstrated in vitro and exploi ...
DOI:
10.1021/acs.jnatprod.9b01066

17. De novo biosynthesis of indole-3-ethanol and indole-3-ethanol acetate in engineered Escherichia coli

Author:
Kong, Sijia; Zhang, Jianbi; Li, Xun; Pan, Hong; Guo, Daoyi
Source:
Biochemical engineering journal 2020 v.154 pp. 107432
ISSN:
1369-703X
Subject:
acetates,   etc   ; Escherichia coli; acetyltransferases; alcohols; biosynthesis; carbon; glucose; tryptophan;     Show all 8 Subjects
Abstract:
... Indole-3-ethanol is an important pharmaceutical intermediate that possess significant pharmaceutical properties. In this study, we established an artificial pathway in engineered Escherichia coli for microbial production of indole-3-ethanol from simple carbon sources. The overall pathway includes the upstream pathway from glucose to L-tryptophan and the downstream pathway from L-tryptophan to indo ...
DOI:
10.1016/j.bej.2019.107432

18. Sulfur-mediated difunctionalization of internal and terminal alkynes for the synthesis of α-acetoxy ketones

Author:
Zhang, Zhong; Li, Pingfan
Source:
Tetrahedron letters 2020 pp. 151707
ISSN:
0040-4039
Subject:
acetates,   etc   ; Lewis bases; alkynes; chemical reactions; chemical structure; ketones; potassium;     Show all 7 Subjects
Abstract:
... The sulfur-mediated difunctionalization of alkynes is reported to give α-acetoxy ketones in a one-pot operation under mild conditions with 19–92% yield. By using wet potassium acetate as both the aqueous base and nucleophilic reagent, both terminal alkynes and internal alkynes could be converted into the α-acetoxy ketone products. ...
DOI:
10.1016/j.tetlet.2020.151707

19. Improvement of the efficiency of solar thermal energy storage systems by cascading a PCM unit with a water tank

Author:
Huang, Haotian; Xiao, Yimin; Lin, Jianquan; Zhou, Tiecheng; Liu, Yanan; Zhao, Qian
Source:
Journal of cleaner production 2020 v.245 pp. 118864
ISSN:
0959-6526
Subject:
sodium acetate,   etc   ; computer software; heat; heating systems; models; supercooling; temperature;     Show all 7 Subjects
Abstract:
... For solar heating systems, adding phase change material (PCM) can significantly increase the thermal storage capacity. This paper proposes a system using a PCM thermal storage unit cascadely combined with a water tank and configures a composite PCM suitable for the system. This study investigates the impact of this system configuration on the system efficiency while developing a matching principle ...
DOI:
10.1016/j.jclepro.2019.118864

20. Copper-Catalyzed Asymmetric Propargylic Alkylation with Oxindoles: Diastereo- and Enantioselective Construction of Vicinal Tertiary and All-Carbon Quaternary Stereocenters

Author:
Xia, Jin-Tao; Hu, Xiang-Ping
Source:
Organic letters 2020 v.22 no.3 pp. 1102-1107
ISSN:
1523-7052
Subject:
acetates,   etc   ; acetonitrile; alkylation; catalytic activity; chemical structure; copper; enantioselectivity; ligands;     Show all 8 Subjects
Abstract:
... A copper-catalyzed asymmetric propargylic alkylation of propargylic acetates with 3-substituted oxindoles for the stereoselective construction of vicinal tertiary and all-carbon quaternary stereocenters in a 3,3-disubstituted oxindole skeleton has been realized. The reaction proceeded smoothly under the catalysis of Cu(MeCN)₄PF₆ combined with a chiral tridentate ferrocenyl P,N,N ligand, leading to ...
DOI:
10.1021/acs.orglett.9b04621