Unexpected dealkylation of Bischler-Napieralski cyclization of 2-(3,4-dimethoxy-2- nitro-phenyl)-N-[2-(3,4-dimethoxyphenyl) ethyl]-N-[(S)-1-phenyl-ethyl] acetamide 3 was reported. The electronic effect of the substitu...Unexpected dealkylation of Bischler-Napieralski cyclization of 2-(3,4-dimethoxy-2- nitro-phenyl)-N-[2-(3,4-dimethoxyphenyl) ethyl]-N-[(S)-1-phenyl-ethyl] acetamide 3 was reported. The electronic effect of the substituent at 2-position of C ring was also discussed.展开更多
The reaction of HFe_2Co(CO)_9(μ_3-S)with(η~5-C_5H_4CH_3)Mo(CO)_3CI has been carried out in refluxing tetrahydrofuran(THF)to give out heterometallic trinuclear clusters(η~5-C_5H_4CH_3)MoFeCo- (CO)_8(μ_3-S)and(η~5-...The reaction of HFe_2Co(CO)_9(μ_3-S)with(η~5-C_5H_4CH_3)Mo(CO)_3CI has been carried out in refluxing tetrahydrofuran(THF)to give out heterometallic trinuclear clusters(η~5-C_5H_4CH_3)MoFeCo- (CO)_8(μ_3-S)and(η~5-C_5H_4CH_3)_2Mo_2Fe(CO)_7(μ_3-S)by electrophilic addition-elimination reaction.Howev- er,(η~5-C_5H_4CH_3)Fe(CO)_2Cl reacted with HFe_2Co(CO)_9(μ_3-S)at room temperature to yield a tetranuclear cluster(η~5-C_5H_4CH_3)Fe_3Co(CO)_(11)(μ_4-S).The μ_4-S cluster could be used as an intermediate in confirmation of the mechanism of the electrophilic addition-elimination reaction.The syntheses,characterizations and X-ray crystal structures of these clusters are reported herein as well as the discussion on the reaction mecha- nism.展开更多
Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound w...Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.展开更多
The reaction mechanisms between formaldehyde and MoOx(x = 1, 2, 3) have been studied thoroughly in this paper. Five reaction pathways were found in three reactions(reactions Ⅰ to Ⅲ) through studying the mechanisms o...The reaction mechanisms between formaldehyde and MoOx(x = 1, 2, 3) have been studied thoroughly in this paper. Five reaction pathways were found in three reactions(reactions Ⅰ to Ⅲ) through studying the mechanisms of MoOx(x = 1, 2, 3) catalyzing formaldehyde. Different products were obtained from three reactions. Of all three reactions, the barrier energy of Route ⅡA is the lowest(4.70 kcal/mol), which means in MoOx(x = 1, 2, 3), MoO2 has the best catalytic effect. Compared with other similar non-toxic treatments of formaldehyde, our barrier energy is the lowest. In this research, there was no good leaving group of the compound, so the mechanisms are addition reaction. We speculate that there must be an addition reaction to the more complex reactions to molybdenum oxides and aldehydes. As a chemical reagent for removing formaldehyde, it only absorbs formaldehyde and does not emit other toxic substances outward. Molybdenum oxides retain its original structures of the final products, which means it has excellent stability in the reaction of MoOx(x = 1, 2, 3) + HCHO. The mechanisms of all three reactions are addition reactions, but they are entirely different. As the number of oxygen atoms increases, the reaction mechanisms become simpler.展开更多
Starting from（5S）-（L-menthyloxy）-3,4-dibromo-5H-furan-2-one and L-leucine,the title compound N-[（2S）-4-bromo-2-（L-menthyloxy）-5-oxo-2,5-dihydro-3-furyl]-L-leucine 5（C20H32BrNO5,Mr = 446.37） was obtained in o...Starting from（5S）-（L-menthyloxy）-3,4-dibromo-5H-furan-2-one and L-leucine,the title compound N-[（2S）-4-bromo-2-（L-menthyloxy）-5-oxo-2,5-dihydro-3-furyl]-L-leucine 5（C20H32BrNO5,Mr = 446.37） was obtained in one-pot process via the tandem Michael addition-elimination reaction in the presence of potassium hydroxide.The chemical structure and absolute configuration of the title compound were confirmed via rotation,UV-Vis,FT-IR,1H NMR,13C NMR,MS and elemental analysis,especially by the X-ray single-crystal diffraction.The crystal crystallizes in an orthorhombic system,space group P212121 with a = 12.5249（16）,b = 19.005（3）,c = 19.719（3） ,V = 4693.7（10） 3,Z = 8,Dc = 1.263 g/m3,μ = 1.778 mm-1,F（000） = 1872,the final R = 0.0617 and wR = 0.1576 for 3967 observed reflections（I 2σ（I））.X-ray analysis reveals that the title compound has two independent molecules in the asymmetric part of the unit cell with the two five-membered furanones being almost planar.The essential part of the electron delocalization is concentrated in the N（1）,C（3）,C（1）,C（37） and O（7） region and N（2）,C（28）,C（27）,C（30） and O（4） region in the other molecule respectively,but does not take place at the expense of delocalization within the ester function.展开更多
A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of ...A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of aromatic aldehydes and cyclohexane-1,3-diones. This transformation proceeded without any metal catalyst in non-toxic solvent at room temperature with high isolated yields. A plausible mechanism for this process was pro- posed.展开更多
文摘Unexpected dealkylation of Bischler-Napieralski cyclization of 2-(3,4-dimethoxy-2- nitro-phenyl)-N-[2-(3,4-dimethoxyphenyl) ethyl]-N-[(S)-1-phenyl-ethyl] acetamide 3 was reported. The electronic effect of the substituent at 2-position of C ring was also discussed.
文摘The reaction of HFe_2Co(CO)_9(μ_3-S)with(η~5-C_5H_4CH_3)Mo(CO)_3CI has been carried out in refluxing tetrahydrofuran(THF)to give out heterometallic trinuclear clusters(η~5-C_5H_4CH_3)MoFeCo- (CO)_8(μ_3-S)and(η~5-C_5H_4CH_3)_2Mo_2Fe(CO)_7(μ_3-S)by electrophilic addition-elimination reaction.Howev- er,(η~5-C_5H_4CH_3)Fe(CO)_2Cl reacted with HFe_2Co(CO)_9(μ_3-S)at room temperature to yield a tetranuclear cluster(η~5-C_5H_4CH_3)Fe_3Co(CO)_(11)(μ_4-S).The μ_4-S cluster could be used as an intermediate in confirmation of the mechanism of the electrophilic addition-elimination reaction.The syntheses,characterizations and X-ray crystal structures of these clusters are reported herein as well as the discussion on the reaction mecha- nism.
文摘Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.
基金supported by the school fund of Shanxi Institute of technology(201605001,20180010012)the 2016 annual major science and technology projects of Shanxi Province(MC2016-02/5)+2 种基金the Shanxi Advantageous and Characteristic Disciplines of “Project 1331”the National Natural Science Foundation of China(No.21373025)the major project of Tangshan Normal College(Nos.2017B01 and 2017B02)
文摘The reaction mechanisms between formaldehyde and MoOx(x = 1, 2, 3) have been studied thoroughly in this paper. Five reaction pathways were found in three reactions(reactions Ⅰ to Ⅲ) through studying the mechanisms of MoOx(x = 1, 2, 3) catalyzing formaldehyde. Different products were obtained from three reactions. Of all three reactions, the barrier energy of Route ⅡA is the lowest(4.70 kcal/mol), which means in MoOx(x = 1, 2, 3), MoO2 has the best catalytic effect. Compared with other similar non-toxic treatments of formaldehyde, our barrier energy is the lowest. In this research, there was no good leaving group of the compound, so the mechanisms are addition reaction. We speculate that there must be an addition reaction to the more complex reactions to molybdenum oxides and aldehydes. As a chemical reagent for removing formaldehyde, it only absorbs formaldehyde and does not emit other toxic substances outward. Molybdenum oxides retain its original structures of the final products, which means it has excellent stability in the reaction of MoOx(x = 1, 2, 3) + HCHO. The mechanisms of all three reactions are addition reactions, but they are entirely different. As the number of oxygen atoms increases, the reaction mechanisms become simpler.
基金Supported by the National Natural Science Foundation of China (No. 20772035)the Natural Science Foundation of Guangdong Province (No. 5300082)
文摘Starting from（5S）-（L-menthyloxy）-3,4-dibromo-5H-furan-2-one and L-leucine,the title compound N-[（2S）-4-bromo-2-（L-menthyloxy）-5-oxo-2,5-dihydro-3-furyl]-L-leucine 5（C20H32BrNO5,Mr = 446.37） was obtained in one-pot process via the tandem Michael addition-elimination reaction in the presence of potassium hydroxide.The chemical structure and absolute configuration of the title compound were confirmed via rotation,UV-Vis,FT-IR,1H NMR,13C NMR,MS and elemental analysis,especially by the X-ray single-crystal diffraction.The crystal crystallizes in an orthorhombic system,space group P212121 with a = 12.5249（16）,b = 19.005（3）,c = 19.719（3） ,V = 4693.7（10） 3,Z = 8,Dc = 1.263 g/m3,μ = 1.778 mm-1,F（000） = 1872,the final R = 0.0617 and wR = 0.1576 for 3967 observed reflections（I 2σ（I））.X-ray analysis reveals that the title compound has two independent molecules in the asymmetric part of the unit cell with the two five-membered furanones being almost planar.The essential part of the electron delocalization is concentrated in the N（1）,C（3）,C（1）,C（37） and O（7） region and N（2）,C（28）,C（27）,C（30） and O（4） region in the other molecule respectively,but does not take place at the expense of delocalization within the ester function.
基金Supported by the National Natural Science Foundation of China（Nos.21772001, 21372008）, the Natural Science Foundation of Education Administration of Anhui Province, China（No.KJ2016A267）, the Special and Excellent Research Fund of Anhui Normal Universit and the Doctoral Scientific Research Foundation of Anhui Normal University, China（No.2016XJJ110）.
文摘A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of aromatic aldehydes and cyclohexane-1,3-diones. This transformation proceeded without any metal catalyst in non-toxic solvent at room temperature with high isolated yields. A plausible mechanism for this process was pro- posed.
