This paper reports that low-temperature heat capacities of N-methylnorephedrine C11H17NO（s） have been measured by a precision automated adiabatic calorimeter over the temperature range from T=78K to T=400K. A solid ...This paper reports that low-temperature heat capacities of N-methylnorephedrine C11H17NO（s） have been measured by a precision automated adiabatic calorimeter over the temperature range from T=78K to T=400K. A solid to liquid phase transition of the compound was found in the heat capacity curve in the temperature range of T=342-364 K. The peak temperature, molar enthalpy and entropy of fusion of the substance were determined. The experimental values of the molar heat capacities in the temperature regions of T=78-342 K and T=364-400 K were fitted to two poly- nomial equations of heat capacities with the reduced temperatures by least squares method. The smoothed molar heat capacities and thermodynamic functions of N-methylnorephedrine C11H17NO（s） relative to the standard refer- ence temperature 298.15 K were calculated based on the fitted polynomials and tabulated with an interval of 5 K. The constant-volume energy of combustion of the compound at T=298.15 K was measured by means of an isoperibol precision oxygen-bomb combustion calorimeter. The standard molar enthalpy of combustion of the sample was calculated. The standard molar enthalpy of formation of the compound was determined from the combustion enthalpy and other auxiliary thermodynamic data through a Hess thermochemical cycle.展开更多
A heterogeneous metal-organic cage based on Rh-Rh bonds [Rh4（pbeddb）4（H2O）2（DMAC）2] （MOC-18; pbeddb2- = 3,3＇-（1,3-phenylenebis（ethyne-2,1-diyl））dibenzoate） was applied to the N-- H insertion reactions wit...A heterogeneous metal-organic cage based on Rh-Rh bonds [Rh4（pbeddb）4（H2O）2（DMAC）2] （MOC-18; pbeddb2- = 3,3＇-（1,3-phenylenebis（ethyne-2,1-diyl））dibenzoate） was applied to the N-- H insertion reactions with diazo compounds. This method offered an environmentally friendly and highly efficient approach for C--N bond formation.展开更多
Potassium tert-butoxide has been found to be a highly efficient catalyst for one-pot,three-component reaction of aryl aldehydes, acetophenones,and thiols via Claisen-Schmidt/Michael addition reactions for the synthesi...Potassium tert-butoxide has been found to be a highly efficient catalyst for one-pot,three-component reaction of aryl aldehydes, acetophenones,and thiols via Claisen-Schmidt/Michael addition reactions for the synthesis of thia-Michael adducts in high yields. The reactions are best carried out in tert-butyl alcohol at room temperature.展开更多
We describe an iron-catalyzed amide bond formation from readily available carboxylic acids and isocyanates.This method utilizes an abundant and biocompatible iron catalyst and easily accessible starting materials,gene...We describe an iron-catalyzed amide bond formation from readily available carboxylic acids and isocyanates.This method utilizes an abundant and biocompatible iron catalyst and easily accessible starting materials,generates CO_(2) as the only byproduct,and features broad substrate scopes with good functional group compatibility.Therefore,it provides a cost-effective and practical protocol to access a diverse variety of amides.展开更多
Alternating current(AC)electrolysis is a promising,yet challenging,and under-developed protocol in organic synthesis.To achieve as high an atomefficiency as possible and avoid the use of external oxidant,electrochemis...Alternating current(AC)electrolysis is a promising,yet challenging,and under-developed protocol in organic synthesis.To achieve as high an atomefficiency as possible and avoid the use of external oxidant,electrochemistry has become a standard organic synthesis tool.Herein,an AC-basedprotocol is a superior option than its counterpart,direct current(DC),especially for those reactions that cannot be accomplished by DC.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 20673050）.
文摘This paper reports that low-temperature heat capacities of N-methylnorephedrine C11H17NO（s） have been measured by a precision automated adiabatic calorimeter over the temperature range from T=78K to T=400K. A solid to liquid phase transition of the compound was found in the heat capacity curve in the temperature range of T=342-364 K. The peak temperature, molar enthalpy and entropy of fusion of the substance were determined. The experimental values of the molar heat capacities in the temperature regions of T=78-342 K and T=364-400 K were fitted to two poly- nomial equations of heat capacities with the reduced temperatures by least squares method. The smoothed molar heat capacities and thermodynamic functions of N-methylnorephedrine C11H17NO（s） relative to the standard refer- ence temperature 298.15 K were calculated based on the fitted polynomials and tabulated with an interval of 5 K. The constant-volume energy of combustion of the compound at T=298.15 K was measured by means of an isoperibol precision oxygen-bomb combustion calorimeter. The standard molar enthalpy of combustion of the sample was calculated. The standard molar enthalpy of formation of the compound was determined from the combustion enthalpy and other auxiliary thermodynamic data through a Hess thermochemical cycle.
文摘A heterogeneous metal-organic cage based on Rh-Rh bonds [Rh4（pbeddb）4（H2O）2（DMAC）2] （MOC-18; pbeddb2- = 3,3＇-（1,3-phenylenebis（ethyne-2,1-diyl））dibenzoate） was applied to the N-- H insertion reactions with diazo compounds. This method offered an environmentally friendly and highly efficient approach for C--N bond formation.
文摘Potassium tert-butoxide has been found to be a highly efficient catalyst for one-pot,three-component reaction of aryl aldehydes, acetophenones,and thiols via Claisen-Schmidt/Michael addition reactions for the synthesis of thia-Michael adducts in high yields. The reactions are best carried out in tert-butyl alcohol at room temperature.
基金the National Natural Science Foundation of China(2207118522271224)Wuhan University startup funding for financial support.
文摘We describe an iron-catalyzed amide bond formation from readily available carboxylic acids and isocyanates.This method utilizes an abundant and biocompatible iron catalyst and easily accessible starting materials,generates CO_(2) as the only byproduct,and features broad substrate scopes with good functional group compatibility.Therefore,it provides a cost-effective and practical protocol to access a diverse variety of amides.
基金supported by the National Natural Science Foundation of China(no.22031008)and the Science Foundation of Wuhan(no.2020010601012192).
文摘Alternating current(AC)electrolysis is a promising,yet challenging,and under-developed protocol in organic synthesis.To achieve as high an atomefficiency as possible and avoid the use of external oxidant,electrochemistry has become a standard organic synthesis tool.Herein,an AC-basedprotocol is a superior option than its counterpart,direct current(DC),especially for those reactions that cannot be accomplished by DC.
