Anhydrous Cu(OAc)<sub>2</sub> mediated efficient protocol has been developed in the area of C-O coupling from potassium aryltrifluoroborates and aliphatic amino alcohols such as β-hydroxy, γ-hydroxy, and...Anhydrous Cu(OAc)<sub>2</sub> mediated efficient protocol has been developed in the area of C-O coupling from potassium aryltrifluoroborates and aliphatic amino alcohols such as β-hydroxy, γ-hydroxy, and δ-hydroxy amines. The scope of this transformation focuses on direct O-arylation and O-styrylation. The reaction vial loaded with reactants under argon atmosphere is microwaved at 140°C for 30 min to furnish the corresponding cross-coupling product, amino ethers, in good yields.展开更多
An efficient and novel methodology to access phenolic glycosides has been established by using coppermediated coupling reaction of aryl boronic acids with hemiacetals.The reaction takes place normally in the presence ...An efficient and novel methodology to access phenolic glycosides has been established by using coppermediated coupling reaction of aryl boronic acids with hemiacetals.The reaction takes place normally in the presence of Cu(OAc)_2(1.0 equiv.)and pyridine(2.0 equiv.)at 40℃.This protocol distinguishes itself by wide substrate scope,operational simplicity and giving rise to a myriad of phenolic glycosides in good to excellent yields.展开更多
A Cu2O/SiC heterogeneous catalyst was prepared via a two‐step liquid‐phase method using diethyleneglycol as both the solvent and the reducing agent.The catalyst was characterized using X‐raydiffraction,X‐ray photo...A Cu2O/SiC heterogeneous catalyst was prepared via a two‐step liquid‐phase method using diethyleneglycol as both the solvent and the reducing agent.The catalyst was characterized using X‐raydiffraction,X‐ray photoelectron spectroscopy,scanning electron microscopy(SEM),transmissionelectron microscopy(TEM),and H2temperature‐programmed reduction.All the results indicatethat Cu is present on the SiC support primarily as Cu2O.The SEM and TEM results show that cubicCu2O nanoparticles are uniformly dispersed on theβ‐SiC surface.The reaction conditions,namelythe temperature,reaction time,and amounts of base and catalyst used,for the Ullmann‐type C–Ocross‐coupling reaction were optimized.A model reaction was performed using iodobenzene(14.0mmol)and phenol(14.0mmol)with Cu2O/SiC(5wt%Cu)as the catalyst,Cs2CO3(1.0equiv.)as thebase,and tetrahydrofuran as the solvent at150°C for3h;a yield of97%was obtained and theturnover frequency(TOF)was1136h?1.The Cu2O/SiC catalyst has a broad substrate scope and canbe used in Ullmann‐type C–O cross‐coupling reactions of aryl halides and phenols bearing a varietyof different substituents.The catalyst also showed high activity in the Ullmann‐type C–Scross‐coupling of thiophenol with iodobenzene and substituted iodobenzenes;a TOF of1186h?1was achieved.The recyclability of the Cu2O/SiC catalyst in the O‐arylation of phenol with iodobenzenewas investigated under the optimum conditions.The yield decreased from97%to64%afterfive cycles.The main reason for the decrease in the catalyst activity is loss of the active component,i.e.,Cu2O.展开更多
The thiono-thiolo allylic rearrangement of O-allyl-O-aryl-O-ethyl thionophosphates(1a-j) adsorbed on SiO2 afforded the corresponding O-aryl-O-ethyl-S-allyl thiolophosphates (2a-j) in good yields.
In this letter, the functional-link network (FLN), one of the latest model of neuralnetworks, was used to carry out a detailed QSAR analysis on the series compounds ofO-ethyl-O-aryl-N-isopropyl-phosphoramidothioates w...In this letter, the functional-link network (FLN), one of the latest model of neuralnetworks, was used to carry out a detailed QSAR analysis on the series compounds ofO-ethyl-O-aryl-N-isopropyl-phosphoramidothioates which have high herbicidal activity. FLNis a 2-layer network with simplified structure and has extremely quickened convergence withperfect performance of both fitting and predicting due to the appropriately enhanced展开更多
A computer-assisted retention prediction system (RPS) of fifteen O-ethyl O-aryl N-iso- propyl phosphoramidothioates (1) in reversed-phase HPLC was investigated. The system is based on the use of four physicochemical p...A computer-assisted retention prediction system (RPS) of fifteen O-ethyl O-aryl N-iso- propyl phosphoramidothioates (1) in reversed-phase HPLC was investigated. The system is based on the use of four physicochemical parameters (hydrophobicity , electric effect σ, field effect F and steric effect ) which is closely related to the retention mechanism in reversed-phase HPLC. The system was evaluated by comparing the measured retention data with the predicted ones. The predicted values were consistent with the measured values within a relative error of 11.5%.展开更多
文摘Anhydrous Cu(OAc)<sub>2</sub> mediated efficient protocol has been developed in the area of C-O coupling from potassium aryltrifluoroborates and aliphatic amino alcohols such as β-hydroxy, γ-hydroxy, and δ-hydroxy amines. The scope of this transformation focuses on direct O-arylation and O-styrylation. The reaction vial loaded with reactants under argon atmosphere is microwaved at 140°C for 30 min to furnish the corresponding cross-coupling product, amino ethers, in good yields.
基金financially supported by the National Key R&D Program of China (No. 2018YFA0507602)the National Natural Science Foundation of China (Nos. 21572012, 21772006)the State Key Laboratory of Drug Research (No. SIMM1803KF-02)
文摘An efficient and novel methodology to access phenolic glycosides has been established by using coppermediated coupling reaction of aryl boronic acids with hemiacetals.The reaction takes place normally in the presence of Cu(OAc)_2(1.0 equiv.)and pyridine(2.0 equiv.)at 40℃.This protocol distinguishes itself by wide substrate scope,operational simplicity and giving rise to a myriad of phenolic glycosides in good to excellent yields.
基金supported by the National Natural Science Foundation of China (21203233,21473232,21403270)Youth Innovation Promotion Association,CAS (2013115)~~
文摘A Cu2O/SiC heterogeneous catalyst was prepared via a two‐step liquid‐phase method using diethyleneglycol as both the solvent and the reducing agent.The catalyst was characterized using X‐raydiffraction,X‐ray photoelectron spectroscopy,scanning electron microscopy(SEM),transmissionelectron microscopy(TEM),and H2temperature‐programmed reduction.All the results indicatethat Cu is present on the SiC support primarily as Cu2O.The SEM and TEM results show that cubicCu2O nanoparticles are uniformly dispersed on theβ‐SiC surface.The reaction conditions,namelythe temperature,reaction time,and amounts of base and catalyst used,for the Ullmann‐type C–Ocross‐coupling reaction were optimized.A model reaction was performed using iodobenzene(14.0mmol)and phenol(14.0mmol)with Cu2O/SiC(5wt%Cu)as the catalyst,Cs2CO3(1.0equiv.)as thebase,and tetrahydrofuran as the solvent at150°C for3h;a yield of97%was obtained and theturnover frequency(TOF)was1136h?1.The Cu2O/SiC catalyst has a broad substrate scope and canbe used in Ullmann‐type C–O cross‐coupling reactions of aryl halides and phenols bearing a varietyof different substituents.The catalyst also showed high activity in the Ullmann‐type C–Scross‐coupling of thiophenol with iodobenzene and substituted iodobenzenes;a TOF of1186h?1was achieved.The recyclability of the Cu2O/SiC catalyst in the O‐arylation of phenol with iodobenzenewas investigated under the optimum conditions.The yield decreased from97%to64%afterfive cycles.The main reason for the decrease in the catalyst activity is loss of the active component,i.e.,Cu2O.
文摘The thiono-thiolo allylic rearrangement of O-allyl-O-aryl-O-ethyl thionophosphates(1a-j) adsorbed on SiO2 afforded the corresponding O-aryl-O-ethyl-S-allyl thiolophosphates (2a-j) in good yields.
基金Project supported by the National Natural Science Foundation of China.
文摘In this letter, the functional-link network (FLN), one of the latest model of neuralnetworks, was used to carry out a detailed QSAR analysis on the series compounds ofO-ethyl-O-aryl-N-isopropyl-phosphoramidothioates which have high herbicidal activity. FLNis a 2-layer network with simplified structure and has extremely quickened convergence withperfect performance of both fitting and predicting due to the appropriately enhanced
文摘A computer-assisted retention prediction system (RPS) of fifteen O-ethyl O-aryl N-iso- propyl phosphoramidothioates (1) in reversed-phase HPLC was investigated. The system is based on the use of four physicochemical parameters (hydrophobicity , electric effect σ, field effect F and steric effect ) which is closely related to the retention mechanism in reversed-phase HPLC. The system was evaluated by comparing the measured retention data with the predicted ones. The predicted values were consistent with the measured values within a relative error of 11.5%.
