scholarly journals 4-Cyano-3-oxotetrahydrothiophene (c-THT): An Ideal Acrylonitrile Anion Equivalent

SynOpen ◽  
2021 ◽  
Vol 05 (01) ◽  
pp. 25-28
Author(s):  
Stellios Arseniyadis ◽  
François Richard ◽  
Carlos Mateos

Abstract4-Cyano-3-oxotetrahydrothiophene (c-THT) has much more to offer than just a platform to various heterocyclic scaffolds. This solid, bench-stable and commercially available reagent can be readily transformed into thioglycolic acid and acrylonitrile upon simple addition of a hydroxide anion. This interesting feature enables its use as a particularly versatile acrylonitrile anion surrogate.

2011 ◽  
Vol 70 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Muriel Fanget ◽  
Catherine Thevenot ◽  
Caroline Castel ◽  
Michel Fayol

In this study, we used a paradigm recently developed ( Thevenot, Fanget, & Fayol, 2007 ) to determine whether 10-year-old children solve simple addition problems by retrieval of the answer from long-term memory or by calculation procedures. Our paradigm is unique in that it does not rely on reaction times or verbal reports, which are known to potentially bias the results, especially in children. Rather, it takes advantage of the fact that calculation procedures degrade the memory traces of the operands, so that it is more difficult to recognize them when they have been involved in the solution of an addition problem by calculation rather than by retrieval. The present study sharpens the current conclusions in the literature and shows that, when the sum of addition problems is up to 10, children mainly use retrieval, but when it is greater than 10, they mainly use calculation procedures.


1987 ◽  
Vol 52 (10) ◽  
pp. 2482-2491 ◽  
Author(s):  
Ján Urban ◽  
Petr Kuzmič ◽  
David Šaman ◽  
Milan Souček

Anaerobic photolysis of dimethoxynitrobiphenyls IIIa-VIa in aqueous alkaline tert-butanol gave products of nucleophilic photosubstitution of methoxyl by hydroxide anion, while the dimethoxybiphenyls Ia and IIa were found unreactive. Regioselectivity of the reaction was examined in view of a possible “extended meta activation” by the nitro group. The most reactive substrate IIIa gives both C-3 and C-4 substitution products with an unsubstantial preference for the latter, which opposes the “extended meta selectivity” rule. All of the other compounds obey the rule, and 3,4-dimethoxy-3'-nitrobiphenyl (IVa) even displayed absolute selectivity by yielding C-3 substituted compound as the only product. 2,5-Dimethoxy substituted compounds underwent photosubstitution which much lower quantum yields than their 3,4-substituted counterparts, most probably due to some steric hindrance of conjugation. Similarly, 3-nitro-substituted biphenyls exhibited much lower overall reactivity than 4-nitro derivatives.


1975 ◽  
Vol 12 (2) ◽  
pp. 289-299 ◽  
Author(s):  
Richard A. F. Grieve ◽  
John Gittins

Coronas of orthopyroxene, amphibole and spinel, and occasional garnet occur between olivine and plagioclase in olivine gabbros and troctolites of the Hadlington gabbroic complex. Microprobe analyses show that changes in olivine composition are mirrored in the composition of the corona minerals. Textural evidence indicates that corona formation was sub-solidus and Mg–Fe partitioning between ortho- and clinopyroxene suggests temperatures below 850 °C. Calculations of earlier models for corona formation based on equal volume replacement, or the simple addition of silica or alumina, fail to yield a satisfactory chemical balance. Olivine and plagioclase, with the addition of water, can supply the material needed for corona formation only if a migrating reaction boundary and change in olivine composition are considered.


2021 ◽  
Vol 224 ◽  
pp. 110990
Author(s):  
Saad Sarwar ◽  
Sunghyeok Park ◽  
Thuy Thi Dao ◽  
Sungjun Hong ◽  
Chi-Hwan Han
Keyword(s):  

2020 ◽  
pp. 1-11
Author(s):  
Dawei Yu ◽  
Jie Yang ◽  
Yun Zhang ◽  
Shujuan Yu

The Densely Connected Network (DenseNet) has been widely recognized as a highly competitive architecture in Deep Neural Networks. And its most outstanding property is called Dense Connections, which represent each layer’s input by concatenating all the preceding layers’ outputs and thus improve the performance by encouraging feature reuse to the extreme. However, it is Dense Connections that cause the challenge of dimension-enlarging, making DenseNet very resource-intensive and low efficiency. In the light of this, inspired by the Residual Network (ResNet), we propose an improved DenseNet named Additive DenseNet, which features replacing concatenation operations (used in Dense Connections) with addition operations (used in ResNet), and in terms of feature reuse, it upgrades addition operations to accumulating operations (namely ∑ (·)), thus enables each layer’s input to be the summation of all the preceding layers’ outputs. Consequently, Additive DenseNet can not only preserve the dimension of input from enlarging, but also retain the effect of Dense Connections. In this paper, Additive DenseNet is applied to text classification task. The experimental results reveal that compared to DenseNet, our Additive DenseNet can reduce the model complexity by a large margin, such as GPU memory usage and quantity of parameters. And despite its high resource economy, Additive DenseNet can still outperform DenseNet on 6 text classification datasets in terms of accuracy and show competitive performance for model training.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Adedibu C. Tella ◽  
Janet T. Bamgbose ◽  
Vincent O. Adimula ◽  
Mary Omotoso ◽  
Sunday E. Elaigwu ◽  
...  

AbstractThe interaction of eosin B dye from aqueous solution with MIL-100(Fe) and functionalized MIL-100(Fe) metal–organic frameworks (MOFs) is reported in this study. MIL-100(Fe) was prepared and functionalized with thioglycolic acid (TH) and ethylenediammine (ED) separately by incorporating the thiol (–SH) and the amine (–NH2) group of the functionalizing agents into the open metal sites of the MIL-100(Fe) to obtain the acidic (TH-MIL-100) and basic (ED-MIL-100) forms of the MOF respectively. Characterization of the MOFs was done by melting point analysis, elemental analysis, spectroscopic techniques, scanning electron microscopy (SEM), and powdered X-ray diffraction (PXRD) analysis. The adsorption experiments were carried out at different conditions such as pH, adsorbent dosage, contact time, temperature, and initial concentration of the dye to estimate the optimum conditions and the maximum adsorption capacities. Adsorption capacities were observed to increase in the order of ED-MIL-100 < MIL-100 < TH-MIL-100, while the TH-MIL-100 was the most effective in the removal process due to acid–base interaction between the acidic thiol group (–SH) and the alkaline medium of eosin B dye solution. The Langmuir Isotherm was seen to fit well to adsorption data obtained for all three adsorbent materials studied, and adsorption processes followed the pseudo-second order kinetics. This study, therefore, indicates the suitability of functionalization of MIL-100(Fe) towards improving its adsorption capacity.


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