21778-19-8Relevant articles and documents
Acid-catalyzed cleavage of 2-pyridyl and 4-pyridyl derivatives of aminomethylphosphonic acid. Kinetic and chemical arguments for a mechanism with A-SE2 character
Boduszek, Bogdan,Latajka, Rafal,Lesniak, Wojciech
, p. 53 - 75 (2000)
Studies of the acid-catalyzed cleavage of 2-pyridyl and 4-pyridyl(amino)methylphosphonic acids demonstrate that protonation has a profound effect on the cleavage of C-P bonds. In H2SO4, and other strong mineral acids the cleavage of aminophosphonic acids 1 and 4 exhibits a kinetic depedence on Zucker-Hammett acidity function (h0), with rate law, v = k[phosphonate]·h0, and also fulfil the Bunnett approach on acidity function. The measured solvent isotope effect kH/kD is small, and varied from 1.46 for 1b to 1.18 for 4b. The isotope effect shows that protons are involved on the rate determining step of the cleavage. All of this evidence indicates that the cleavage of 1 or 4 shows A-SE2 character substitution reaction. Calculated activation parameters and some chemical experiments indicate that the protonated phosphonate molecule is split by a dissociative mechanism, combined with formation of a positive-charged phosphorus moiety.
Dynamic Motion of Organic Ligands in Polar Layered Cobalt Phosphonates
Cai, Zhong-Sheng,Hoshino, Norihisa,Bao, Song-Song,Jia, Jiage,Akutagawa, Tomoyuki,Zheng, Li-Min
, p. 13495 - 13503 (2018/09/19)
By introducing the polar methoxy group into phenyl- or benzyl-phosphonate ligands, four cobalt phosphonates with layered structures are obtained, namely, [Co(4-mopp)(H2O)] (1), [Co(4-mobp)(H2O)] (2), [Co(3-mopp)(H2O)] (3),
Tandem thionation of biomass derived levulinic acid with Lawesson's reagent
Li, Zheng,Tang, Xing,Jiang, Yetao,Zuo, Miao,Wang, Yangjun,Chen, Wei,Zeng, Xianhai,Sun, Yong,Lin, Lu
, p. 2971 - 2975 (2016/06/06)
Herein we report a tandem thionation of biomass derived levulinic acid (LA) to generate thiophenic compounds. LA is initially converted to several thiophenones and then an aromatic di-thionated product, 5-methylthiophene-2-thiol, is obtained with the highest yield of 78%. An overall synthesis of thiophenic products from cellulose is also developed.
Synthesis and proton dissociation properties of arylphosphonates: A microwave-assisted catalytic arbuzov reaction with aryl bromides
Keglevich, Gyoergy,Gruen, Alajos,Boelcskei, Adrienn,Drahos, Laszlo,Kraszni, Marta,Balogh, Gyoergy T.
, p. 574 - 582 (2013/01/15)
A series of substituted diethyl arylphosphonates was synthesized by the microwave-assisted Arbuzov reaction of triethyl phosphite and aryl bromides in the presence of NiCl2 as the catalyst under solvent-free conditions in good yields. The resulting phosphonates were hydrolyzed to the corresponding arylphosphonic acids whose acidity was evaluated by physicochemical methods.
