29523-51-1Relevant articles and documents
Synergetic activation of CO2by the DBU-organocatalyst and amine substrates towards stable carbamate salts for synthesis of oxazolidinones
Chen, Xiao-Chao,Liu, Ye,Lu, Yong,Yao, Yin-Qing,Zhao, Kai-Chun
, p. 7072 - 7082 (2021/11/17)
The development of an efficient methodology to transform CO2 into valuable chemicals has attracted increasing attention concerning the challenging issues of CO2-utilization. Herein, an efficient approach for the preparation of oxazolidinones from CO2, primary (aliphatic/aromatic) amines and 1,2-dichloroethane (or its derivatives) catalyzed by DBU organo-superbase was achieved with yields of 47-97% under mild conditions (80-100 °C, 12 h, 1.0 MPa CO2). Control experiments demonstrated that the formation of an ion-pair carbamate salt intermediate IS-B derived from the reaction of CO2, DBU (catalyst) and an amine (substrate) was the key step for this three-component reaction. The available DBU-amine-CO2 adduct intermediate (like IS-B-2) with fair stability will evolve into the thermodynamically stable product oxazolidinones upon attack of 1,2-dichloroethane (or its derivatives), along with the regeneration of the DBU catalyst. Alternatively, the decomposition of the DBU-aryl amine-CO2 adduct (like IS-B-1) with relatively poor stability also could result in the competitive substitution reaction of 1,2-dichloroethane (or its derivatives) with the aryl amine. This work provides insights into synergetic CO2-activation by the DBU-catalyst and a nucleophilic amine-substrate via the formation of robust carbamate salt intermediates responsible for the final production of oxazolidinones. This journal is
Ag+ ion complexation properties of N-phenylpolythiazaalkane derivatives: Synthesis, crystallography, 1H NMR spectroscopy, potentiometry and metal ion recognition properties
Ishikawa, Junichi,Sakamoto, Hidefumi,Nakamura, Mutsumi,Doi, Kunio,Wada, Hiroko
, p. 191 - 199 (2007/10/03)
A series of N-phenylpolythiazaalkane derivatives; the cyclic derivatives 4-phenyl-1-thia-4-azacyclohexane 1, 7-phenyl-1,4-dithia-7-azacyclononane 2, 10-phenyl-1,4,7-trithia-10-azacyclododecane 3 and 13-phenyl-1 ,4,7,10-tetrathia-13-azacyclopentadecane 4 and acyclic derivatives 6-phenyl-3,9-dithia-6-azaundecane 5 and 9-phenyl-3,6,12,15-tetrathia-9-azaheptadecane 6, have been studied towards complexation with Ag+ ion. Single crystals of two Ag(I) complexes, [Ag(2)2][CF3SO3] and [Ag(4)][CF3SO3] were prepared and their structures were determined in the crystalline state by X-ray diffraction. In [Ag(2)2][CF3SO3], two bidentate 2 ligands, in which two sulfur atoms act as coordination sites, sandwich Ag(I) to give a four-coordinate complex in near tetrahedral geometry. In [Ag(4)], Ag(I) enters into a cavity composed of four sulfur atoms to give a distorted tetrahedral geometry. The changes of the chemical shifts in 1H NMR spectroscopy by the addition of CF3SO3Ag indicate that 1 and 2 exhibit small downfield shifts only for the protons of the thioether moiety, while 3,4,5 and 6 show drastic shifts for all protons. Ag+ ion complexation with N-phenylpolythiazaalkane and polythiaalkane derivatives, which were used for comparison, was studied in acetonitrile solution by potentiometry. Results show that the complex stability is governed primarily by the number of sulfur donor atoms, and the nitrogen atom of the N-phenylpolythiazaalkane derivatives scarcely contributes to the stability of the complexes. The extraction of transition metal ions with N-phenylpolythiazaalkane derivatives was examined and very high Ag+ ion selectivity was observed for most of them. The extraction equilibria of the Ag(I) complexes of N-phenylpolythiazaalkane derivatives were studied and the extraction constants of the extracted complexes determined. Results indicate that the extractability of 1:1 complexes depends on their stability. In liquid membrane transport, all N-phenylpolythiazaalkane derivatives exhibited Ag+ ion selective transportability and the order for the Ag+ ion transport rate was 5 > 2 ≈ 3 > 4 ≈ 6 ? 1.
Silver Ion Selective Extraction with Dithiaza-, Tetrathiaza-, and Tetrathiadiazacrown Ether Derivatives
Sakamoto, Hidefumi,Ishikawa, Junichi,Otomo, Makoto
, p. 2831 - 2836 (2007/10/03)
Dithiazacrown, tetrathiazacrown, and two tetrathiadiazacrown ether derivatives, bearing a phenyl group on each nitrogen atom at the periphery, were synthesized, and the solvent extractions of some transition metal ions with these compounds were carried out using an H2O-1,2-dichloroethane system.All of the thiazacrown compounds employed exhibited Ag+ selectivity, and formed 1:1:1 complexes of Ag+ : ligand : laurate ion as a counter anion to be extracted into a 1,2-dichloroethane solution.The extractabilities (extraction constants, Kex) for Ag+ decreased in the order: 7,16-diphenyltetrathia-7,16-diaza-18-crown-6 (3) (log Kex = 1.18+/-0.13) > 13-phenyltetrathia-13-aza-15-crown-5 (2) (0.75+/-0.09) > 7-phenyldithia-7-aza-9-crown-3 (1) (-0.47+/-0.06)>13, 16-diphenyltetrathia-13,16-diaza-18-crwon-6 (4) (-0.62+/-0.16).
