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141.
A direct and efficient method for the conversion of alkyl aryl ketones to imidazo[1,2‐α]pyridines has been developed based on initial formation of α‐organosulfonyloxy ketones and their subsequent cyclocondensation by 2‐aminopyridines in one‐pot conditions. 相似文献
142.
呋喃甲醛缩二乙撑三胺希夫碱铜配合物的合成及结构(英) 总被引:1,自引:0,他引:1
A novel copper(Ⅱ) complex CuL(NO3)2(where L=N,N′-bis(furaldehyde)-diethylenetriamine) was synthesized and characterized by X-ray crystallography analysis. The crystal belongs to monoclinic, space group C2/c with cell parameters a=1.924 0(6) nm, b=0.792 8(3) nm, c=2.504 1(8) nm, β=111.163(5)°, and Z=8. The coordination geometry around Cu(Ⅱ) is a distorted trigonal-bipyramid,and one-dimensional chain is formed through intermolecular hydrogen bonds. CCDC: 255629. 相似文献
143.
144.
The solid state reaction of 3-methyl-1-phenyl-5-pyrazolone (MPP) with aromatic aldehydes and ke-tones benzil derivatives and imides,and the solid state Michael addition reaction of MPP with 4-arylidene-3-methyl-1-phenyl-5-pyrnzolone 2 were investigated.Some new solid state reactions between the reactants were found,from which a series of new compounds were obtained The structures of the products were identified by IR,1H NMR,MS,elemental analyses and also by X-ray crystal analysis,and the reaction mechanism of MPP with aromatic aldehydes and ketones was proposed 相似文献
145.
Rh/SiO_2上H_2的化学吸附陈耀强,龚茂初,明虹,周建略,杜宗英,祝小红,陈豫(四川大学化学系,成都,610064)关键词Rh/SiO_2催化剂,H_2化学吸附,IRH2在Rh上的化学吸附被认为是解离化学吸附[1].而Rh-H的红外振动谱带是H2在... 相似文献
146.
147.
Recently the hydrogen-bond activated reactions have attracted much attention.1 Takemoto2 reported a highly enantioselective Michael addition of manolate to nitroolefins catalyzed by a bifunctional organocatalyst with tertiary amine and thiourea moiety. As we known,stereoselective conjugate additions of thiols are interesting due to the standpoint of biological and synthetic importance, however, only very limited good results have been obtained except for the works of Shibasaki3, Kanemasa4 and Deng5 et al.In this letter, we report an efficient catalytic asymmetric Michael reactions of thiols to a,a-unsaturated carbonyl compounds promoted by bifunctional organocatalysts. A series of organocatalysts with chiral amine and thiourea structures were designed and synthesized and have been successfully applied in the conjugated additions of thiols to a,a-unsaturated imides and enones.The reactions got quantitative yields and the ee values were up to 84%. It is noteworthy that the a-asymmetric protonation (up to 43% ee) also could be achieved.The Michael addition between aromatic thiols and a,a-unsaturated carbonyl compounds isdescribed as follows:Works to further increase the enantioselectivity is under investigation in our laboratory. 相似文献
148.
Diastereoselective allylation of imine derived from N‐glyoxyloyl camphorpyrazolidinone and amines was treated with allyltributylstannane in the presence of triflic acid. The corresponding optically enriched homoallylic amines were obtained in reasonable to high material yields and with practical levels of stereoselectivity in 10 min at ambient temperature. 相似文献
149.
150.
In this paper, the spectral behavior of protein and Poniacyl Carmine 2B (PC 2B) has been studied by spectrophotometric method. The conditional constants, apparent combination constant K and maximum binding number n, were used to express the combination ability of the reactions between PC 2B and protein under a set of given conditions. The Sandell index s was used to express the sensitivity of the determination of protein. The factors, acidity, PC 2B concentration and the ionic strength, were discussed by the change of apparent combination constant and maximum binding number. It was found that acidity of the solution, PC 2B concentration and ionic strength had a significant effect on the sensitivity of the assay of protein. Under the optimal conditions, the apparent combination constant K and the maximum binding number n were 2.36 × 106 L mol?1 and 95, respectively. With further investigation, it was found that the Scatchard model was suitable in treating the data obtained in the experiments. In the buffer medium of HCl‐KCl at 1.87, the addition of protein made the maximum absorption of the system move from 527 nm to 513 nm. Its apparent molar absorptivity is 4.46 × 105 Lmol?1 cm?1 at 513 nm. Beer's law is obeyed in the range of 0 ? 55 μg mL?1. The system developed in this paper has been used for the determination of protein in milk powder successfully. 相似文献