17849-38-6Relevant articles and documents
Photoinduced degradation of the herbicide clomazone model reactions for natural and technical systems
David Gara, Pedro M.,Bosio, Gabriela N.,Arce, Valeria B.,Poulsen, Lars,Ogilby, Peter R.,Giudici, Reinaldo,Gonzalez, Monica C.,Martire, Daniel O.
, p. 686 - 692 (2009)
The photodegradation of the herbicide clomazone in the presence of S 2O82- or of humic substances of different origin was investigated. A value of (9.4 ± 0.4) × 108 m-1 s-1 was measured for
Synthesis and reactivity of a hydrido CNC pincer cobalt(III) complex and its application in hydrosilylation of aldehydes and ketones
Zhou, Hongwei,Sun, Hongjian,Zhang, Shumiao,Li, Xiaoyan
, p. 1479 - 1486 (2015)
Reaction of the N-benzylidene-1-naphthylamine with CoMe(PMe3)4 afforded the hydrido CNC pincer cobalt complex CoH(PMe3)2[(C6H4)CH=N(C10H6)] (1) via double C-H bond activation. In the 1H NMR spectrum, a triplet at -18.98 ppm is the typical signal of the hydrido ligand (Co-H). Complex 1 reacted with haloalkane (CH3I and EtBr) to deliver CoX(PMe3)2((C6H4)CH=N(C10H6)) (X = I (2); Br (3)). However, the reactions of complex 1 with HCl and trifluoroacetic acid (TFA) delivered HCoCl(PMe3)2((C6H4)CH=N(C10H7)) (4) and HCo(OCOCF3)(PMe3)2((C6H4)CH=N(C10H7)) (5) with the cleavage of the Co-C(naphthyl) bond. In the 1H NMR spectra, the signals of the hydrido ligands were found at -21.31 (4) and -18.71 (5) ppm. A reaction of complex 1 with DCl was carried out to prove that the hydrogen atom eliminated to the naphthyl carbon comes from HCl. Complex 1 reacted with acetylacetone, resulting in the formation of Co(acac)(PMe3)2((C6H5)CHNH(C10H6)) (7). Complex 1 was found to be an efficient catalyst for hydrosilylation of aldehydes and ketones. The molecular structures of complex 1, 2, 4, and 7 were determined by X-ray single-crystal diffraction.
KINETICS AND MECHANISM OF OXIDATION OF SOME ARYL ALCOHOLS BY ACID BROMATE
Gupta, Kalyan Kali Sen,Kumar, Saroj Chandra,Sen, Pratik Kumar,Banerjee, Amalendu
, p. 2225 - 2232 (1988)
The kinetics of oxidation of some substituted benzyl alcohols as well as the unsubstituted one by bromate ion in hydrochloric acid medium has been suggested.The results indicate that the reaction takes place by way of intermediate ester formation.Methoxy compounds react at much faster rates than the corresponding nitro substituted derivatives.The thermodynamic values associated with the equilibrium step and also for the slow step have been evaluated.A mechanism consistent with the experimental observations has been suggested.
Efficient hydrogenation of benzaldehydes over mesopolymer-entrapped pt nanoparticles in water
Li, Xiaohong,Shen, Yali,Song, Liying,Wang, Hongna,Wu, Haihong,Liu, Yueming,Wu, Peng
, p. 699 - 706 (2009)
Pt nanoparticles entrapped in the matrices of FDU-14 periodic mesoporous organic polymer (abbreviated as mesopolymer), prepared by a simple nd facile method, serve as an efficient catalyst for the liquid-phase hydrogenation of benzaldehydes under mild conditions. Water was confirmed to be a better choice of solvent for the hydrogenation of benzaldehydes on the Pt/FDU-14 catalyst. The highest activity (turnover frequency) was about 5700 mol-1mol -1h-1 for 3-fluorobenzaldehyde hydrogenation in water and no distinct loss of activity or selectivity was observed after the catalyst was recycled nine times. For the para-substituted benzaldehydes, the catalytic performance of Pt/FDU-14 was superior to the commercial Pt/alumina catalyst owing to the more hydrophobic nature of the FDU-based catalyst.
Pt nanoparticles supported on highly dispersed TiO2 coated on SBA-15 as an efficient and recyclable catalyst for liquid-phase hydrogenation
Li, Xiaohong,Zheng, Wenli,Pan, Huiyan,Yu, Yin,Chen, Li,Wu, Peng
, p. 9 - 19 (2013)
A series of TiO2@SBA-15 composites with different TiO 2 loadings have been synthesized through hydrolysis of tetrabutyl orthotitanate via a facile sol-gel method in the presence of SBA-15 mesoporous silica. The TiO2@SBA-15 composites retain the mesostructure of the SBA-15 host, and TiO2 is highly dispersed and uniformly coated. The TiO2@SBA-15 composites serve as remarkable supports for Pt nanoparticles, which can be applied efficiently to the liquid-phase hydrogenation of benzaldehyde, its derivatives, and other unsaturated compounds under mild conditions. Of particular note is that the Pt/TiO2@SBA-15 catalysts can be reused several times without distinct loss in activity or selectivity. The more electron-deficient surface state, together with the structural and physicochemical features of Pt/TiO2@SBA-15 catalysts, would improve the catalytic activity and reusability toward the liquid-phase hydrogenation of unsaturated compounds.
Ru nanoparticles entrapped in ordered mesoporous carbons: An efficient and reusable catalyst for liquid-phase hydrogenation
Ding, Yue,Li, Xiaohong,Pan, Huiyan,Wu, Peng
, p. 268 - 277 (2014)
Ru nanoparticles entrapped in ordered mesoporous carbons (CMK-3) served as an efficient and reusable catalyst for liquid-phase hydrogenation of benzaldehyde and its derivatives under our tested conditions (medium hydrogen pressure, room temperature, water as solvent). The Ru nanoparticles can be well stabilized by CMK-3 ordered mesoporous carbons so that the Ru leaching was below the detection limit of ICP-AES. Therefore, the Ru/CMK-3 catalyst can be used for at least five times without distinct loss in activity or selectivity for the hydrogenation of benzaldehyde. It is worthy of note that the Ru/CMK-3 catalyst was more efficient than the commercial Ru/C and homemade Ru/AC catalyst for the liquid-phase hydrogenation of benzaldehyde. The Ru/ CMK-3 catalyst can also catalyze the liquid-phase hydrogenation of nitrobenzene and its derivatives with high conversions and excellent selectivities under optimal conditions. Springer Science+Business Media New York 2013.
Synthesis and biological evaluation of nigranoic acid esters as novel human neutrophil elastase inhibitors
Huang, Guoli,Feng, Li,Liu, Bo,He, Yi,Li, Yiming,Chen, Yegao
, p. 1650 - 1656 (2015)
Human neutrophil elastase (HNE) has been implicated as a major contributor in the pathogenesis of diseases, such as lung disorders and other inflammatory diseases. A series of 12 new nigranoic acid esters were regioselectively synthesised in good yields and evaluated for HNE inhibitory activity. Nigranoic acid exhibited significant inhibitory activity against HNE with the IC50 value of 3.77 M, and six esters displayed considerable inhibitory effects on HNE with IC50 values in the range of 2.61-8.95 M. The nigranoic acid esters having phenyls substituted with bromine and trimethoxyls (3h and 3b) showed stronger inhibitory activity on HNE than nigranoic acid.
Synthesis of Azido-Dienediols by Enzymatic Dioxygenation of Benzylazides: An Experimental and Theoretical Study
Carrera, Ignacio,Gonzalez, David,Martínez, Sebastián,Seoane, Gustavo,Umpiérrez, Diego,Veiga, Nicolás,Vila, María Agustina,de la Sovera, Victoria
supporting information, (2022/03/01)
Allylic azides are versatile structural motifs in organic synthesis because the proximal double bond enables a [3,3]-sigmatropic rearrangement, named as the Winstein rearrangement. In this work, an experimental and theoretical study on the double Winstein rearrangement occurring in azidodienediols derived from the biocatalytic dihydroxylation of substituted benzylazides is presented. Substrates bearing a methyl group at the ortho or meta position produced exclusively rearranged exo-diendiols with the azide group anti to the diol moiety as the major constituent. In the case of para methyl substrates, an equilibrium mixture of rearranged and non-rearranged products was observed, indicating that a full conversion to the exo-dienediols is not possible within this substitution pattern. On the other hand, the presence of a chloro substituent in the diene moiety completely precluded the Winstein rearrangement to take place, giving rise exclusively to the traditional cis-cyclohexadienediols. The observed results were analyzed to determine the mechanistic and kinetic aspects and scope limitations of the reaction as a synthetic tool.
An efficient method for the cleavage of tert-butyldiphenylsilyl ethers catalyzed by 1,3-dibromo-5,5-dimethylhydantoin
Han, Zong
, p. 51 - 62 (2022/02/14)
An efficient method for the deprotection of tert-butyldiphenylsilyl (TBDPS) ethers using 1,3-dibromo-5,5-dimethylhydantoin (DBH) as catalyst and dimethyl sulfoxide (DMSO) as solvent has been established. This method is useful for many kinds of compounds,
A Bifunctional Copper Catalyst Enables Ester Reduction with H2: Expanding the Reactivity Space of Nucleophilic Copper Hydrides
Kaicharla, Trinadh,Ngoc, Trung Tran,Teichert, Johannes F.,Tzaras, Dimitrios-Ioannis,Zimmermann, Birte M.
supporting information, p. 16865 - 16873 (2021/10/20)
Employing a bifunctional catalyst based on a copper(I)/NHC complex and a guanidine organocatalyst, catalytic ester reductions to alcohols with H2 as terminal reducing agent are facilitated. The approach taken here enables the simultaneous activation of esters through hydrogen bonding and formation of nucleophilic copper(I) hydrides from H2, resulting in a catalytic hydride transfer to esters. The reduction step is further facilitated by a proton shuttle mediated by the guanidinium subunit. This bifunctional approach to ester reductions for the first time shifts the reactivity of generally considered "soft"copper(I) hydrides to previously unreactive "hard"ester electrophiles and paves the way for a replacement of stoichiometric reducing agents by a catalyst and H2.
