Showing papers on "Derivative (chemistry) published in 2019"
TL;DR: The surprising organoboron-mediated catenation of two N2 molecules under near-ambient conditions to form a complex in which a [N4]2– chain bridges two boron centers is reported.
Abstract: The coupling of two or more molecules of dinitrogen (N2) occurs naturally under the radiative conditions present in the ionosphere and may be achieved synthetically under ultrahigh pressure or plasma conditions. However, the comparatively low N-N single-bond enthalpy generally renders the catenation of the strongly triple-bonded N2 diatomic unfavorable and the decomposition of nitrogen chains a common reaction motif. Here, we report the surprising organoboron-mediated catenation of two N2 molecules under near-ambient conditions to form a complex in which a [N4]2- chain bridges two boron centers. The reaction entails reductive coupling of two hypovalent-boron-bound N2 units in a single step. Both this complex and a derivative protonated at both ends of the chain were characterized crystallographically.
171 citations
TL;DR: The synthesis, structural, biological, and catalytic application of Schiff bases as well as their metal complexes are summarized.
170 citations
TL;DR: In this paper, a new derivative aromatic heteroatom epoxy resin synthesized in a laboratory, namely, triglycidyl ether of triethoxy triazine (TGETET), was characterized by FT-IR spectroscopy.
161 citations
TL;DR: This Review demonstrates the breadth of the reactivity and synthetic applications of Petasis reactions in several frontiers: the expansion of the substrate scope in the classic three-component process; nonclassic Petasis reaction with additional components; Petasis-type reactions with noncanonical substrates, mechanism, and products; new asymmetric versions assisted by chiral catalysts.
Abstract: The Petasis boron–Mannich reaction, simply referred to as the Petasis reaction, is a powerful multicomponent coupling reaction of a boronic acid, an amine, and a carbonyl derivative. Highly functio...
143 citations
TL;DR: A Negishi cross-coupling of alkylpyridinium salts and alkylzinc halides has been developed and enables the noncanonical transformation of NH2 groups into a wide range ofAlkyl substituents with broad functional group tolerance.
Abstract: A Negishi cross-coupling of alkylpyridinium salts and alkylzinc halides has been developed. This is the first example of alkyl–alkyl bond formation via cross-coupling of an alkyl amine derivative w...
121 citations
119 citations
118 citations
112 citations
100 citations
96 citations
01 May 2019
TL;DR: The deacetylated derivative of chitin, chitosan, is an interesting bioactive polymer as discussed by the authors, which consists of many reactive primary and secondary hydroxyl (HP) molecules.
Abstract: The deacetylated derivative of chitin i.e. chitosan is an advantageous and interesting bioactive polymer. Despite its biodegradability, it consists of many reactive primary and secondary hydroxyl (...
TL;DR: A combined experimental and theoretical investigation has been reported on N-(glycine)-para styrene sulfonamide (abbreviated as GSS) for first time in two steps.
TL;DR: The asymmetric total synthesis of (-)-viridin and (--viridiol, antifungal metabolite from Gliocladium virens, was achieved in 17 and 18 steps from a commercially available starting material and provides a scalable approach to prepare virid in and viridiol for biological studies.
Abstract: The asymmetric total synthesis of (-)-viridin and (-)-viridiol, antifungal metabolites, was achieved in 17 and 18 steps from a commercially available starting material. An intramolecular [3+2] cycloaddition was applied to an easily available l-ribose derivative in order to construct the highly substituted D ring containing the key chiral cis-triol fragment. Co-catalyzed metal-hydride H atom transfer (MHAT) radical cyclization was utilized to form the C-ring and the all-carbon quaternary center at C-10. This convergent strategy provides a scalable approach to prepare viridin and viridiol for biological studies.
TL;DR: In this article, the potential of a triazole derivative, namely 4,5-diethyl 1-[(4-ethyl-2-phenyl-4,5dihydro-1,3-oxazol-4-yl)methyl], as anticorrosion agent for mild steel (MS) in 1 mol/L HCl solution was investigated using gravimetric and electrochemical techniques.
[...]
TL;DR: In this paper, the equivalence between Riesz derivative and fractional Laplacian on ℝn with n ≥ 1 in details was shown. But, the relation between the two derivatives was not discussed.
Abstract: Abstract This paper focuses on studying Riesz derivative. An interesting investigation on properties of Riesz derivative in one dimension indicates that it is distinct from other fractional derivatives such as Riemann-Liouville derivative and Caputo derivative. In the existing literatures, Riesz derivative is commonly considered as a proxy for fractional Laplacian on ℝ. We show the equivalence between Riesz derivative and fractional Laplacian on ℝn with n ≥ 1 in details.
TL;DR: The improvement of magnetic properties comes from the synergy of optimal single ions properties and exchange couplings contributions where the CoII-Rad interaction becomes the leading one.
Abstract: Coordination compounds containing three different spin carriers (2p, 3d, and 4f), with the general formula [MIIDyIII(LH)(hfac)5] (M = Co, Ni, Mn, Zn), have been obtained using Mannich ligands decorated with a nitronyl-nitroxide fragment. The synthetic approach is general and leads to binuclear 3d-4f complexes, the two metal ions being bridged by one aminoxyl group and by one oxygen atom arising from a hfac- ligand. Triangular spin topology affords significant 2p-3d, 3d-4f, and 2p-4f exchange interactions. For the [CoIIDyIIIRad] derivative obtained using a nitronyl-nitroxide chiral ligand, a high energy barrier (∼200 cm-1) and a slow relaxation behavior below 30 K were found and rationalized by ab initio calculations. The improvement of magnetic properties comes from the synergy of optimal single ions properties and exchange couplings contributions where the CoII-Rad interaction becomes the leading one. The role played by this interaction is clearly proved by the investigation of the magnetic properties of the [ZnIIDyIIIRad] derivative, with a much lower energy barrier (12.7 cm-1) and by the lack of SMM behavior of the previously reported [CoIIDyIIIRad] compound ( Chem. Commun . 2017 , 53 , 6504 ), with a linear topology of spin carriers and a negligible CoII-Rad interaction.
TL;DR: The photoresponse of the coumarin derivative based on reversible photodimerization and photocleavage has been studied for a long time as discussed by the authors, and a novel approach of preparing photoresponsi...
Abstract: The photoresponse of the coumarin derivative based on reversible photodimerization and photocleavage has been studied for a long time. This paper reports a novel approach of preparing photoresponsi...
TL;DR: An aromatic hydrazone derivative, namely (E)-1-(3-nitrobenzylidene)-2-(p-tolyl)hydrazine (E-NBPTH) has been synthesized by condensation of an aromatic hydrine with an aromatic aldehyde in methanol at reflux as mentioned in this paper.
TL;DR: The present study paves the way, for the first time, towards AIE driven dual stimuli response in indeno-pyrrole based D-A fluorophores as a dual sensor for volatile acids and aromatic amines.
Abstract: In the present work, a novel donor (D)–acceptor (A) fluorophore based on indeno-pyrrole derivative (PYROMe) has been utilized as a dual sensor for volatile acids and aromatic amines, where sensory ...
TL;DR: A trisazobenzene macrocycle is presented, which can be switched selectively into three individual states, which are highly attractive for application in data storage or multi-responsive materials.
Abstract: Multi-state photoswitchable compounds are highly attractive for application in data storage or multi-responsive materials. In this work, a trisazobenzene macrocycle capable of three-state isomerization is presented. The compound can be switched into each of the states with more than 70% of the isomer solely by light and heat as stimuli representing the first example for an oligo-azobenzene containing identical photochromic units which can be selectively adressed. Detailed spectroscopic, crystallographic, HPLC as well as computational investigations and the comparison to a less and a higher strained derivative revealed macrocyclic ring strain to be responsible for the compounds unique isomerization behavior.
TL;DR: This study demonstrates that the interplay of Brønsted and Lewis acid sites in zirconium metal-organic frameworks leads to more efficient catalytic conversion of a biomass feedstock to biofuel, and with further hypothesis driven research, additional materials that show promise as candidates for catalytic Conversion of biomass feedstocks to biofuels and valuable chemicals can be developed.
Abstract: We report the performance of UiO-66 and its Bronsted acid functionalized derivative, UiO-66-(COOH)2, as heterogeneous catalysts for levulinic acid esterification with ethanol. Importantly, compared...
TL;DR: A one-dimensional coordination polymer (1D CP) with a paddle-wheel unit exhibits the photosalient effect under UV as well as sunlight irradiation, resembling the popping of popcorn, along with the release of an elusive cyclobutane ligand.
TL;DR: This review describes catalytic asymmetric cycloaddition reactions of silyl-protected enoldiazo compounds for the construction of highly functionalized carbo- and heterocycles which possess one or more chiral center(s).
Abstract: This review describes catalytic asymmetric cycloaddition reactions of silyl-protected enoldiazo compounds for the construction of highly functionalized carbo- and heterocycles which possess one or more chiral center(s). The enoldiazo compound or its derivative, donor-acceptor cyclopropene, form electrophilic vinylogous metal carbene intermediates that combine stepwise with nucleophilic dipolar reactants to form products from [3 + 1]-, [3 + 2]-, [3 + 3]-, [3 + 4]-, and [3 + 5]-cycloaddition, generally in high yield and with exceptional stereocontrol and regioselectivity.
TL;DR: In this article, the authors presented a study supported by the University of Alicante (VIGROB-316) and the Spanish Ministerio de Economia, Industria, and Competitividad (CTQ2015-66624-P, PGC2018-096616-B-100).
Abstract: This work was supported by the University of Alicante (VIGROB-316) and the Spanish Ministerio de Economia, Industria y Competitividad (CTQ2015-66624-P, PGC2018-096616-B-100). BS thanks Generalitat Valenciana (ACIF/2017/211) for a fellowship.
TL;DR: In this article, a new and facile strategy of lignin modification with sustainable levulinic acid to introduce active ketone groups was reported, which exhibited significantly improved solubility and could be utilized to produce polymers such as highperformance polyimine thermosets via the Schiff base reaction with diamines.
TL;DR: The data from structure-actvity relationship (SAR) analysis suggested that phthalimide derivative bearing 3-aminopyrazolone moiety, 4 illustrated the best antimicrobial and antitumor activities and might be considered as a lead for further optimization.
Abstract: Pyrazolylphthalimide derivative 4 was synthesized and reacted with different reagents to afford the target compounds imidazopyrazoles 5-7, pyrazolopyrimidines 9, 12, 14 and pyrazolotriazines 16, 17...