The thermal decomposition behavior and kinetic parameters of the exothermic decomposition reactions of the title compound in a temperature-programmed mode have been investigated by means of DSC, TG-DTG and lower rate ...The thermal decomposition behavior and kinetic parameters of the exothermic decomposition reactions of the title compound in a temperature-programmed mode have been investigated by means of DSC, TG-DTG and lower rate thermolysis/FTIR. The possible reaction mechanism was proposed. The critical temperature of thermal explo-sion was calculated. The influence of the title compound on the combustion characteristic of composite modified double base propellant containing RDX has been explored with the strand burner. The results show that the kinetic model function in differential form, apparent activation energy Ea and pre-exponential factor A of the major exo-thermic decomposition reaction are 1-a, 207.98 kJmol-1 and 1015.64 s-1, respectively. The critical temperature of thermal explosion of the compound is 312.87 ℃. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as: ()416.422.502?d101 edTTaa-10=-. As an auxiliary catalyst, the title compound can help the main catalyst lead salt of 4-hydroxy-3,5-dinitropyridine oxide to en-hance the burning rate and reduce the pressure exponent of RDX-CMDB propellant.展开更多
Pd-catalyzed cross-coupling reactions of chloropyrimidines with alkenylboronic acids readily proceed to give the corresponding alkenylpyrimidines in high to excellent yields. The coupling reaction of 2,4-dichloropyrim...Pd-catalyzed cross-coupling reactions of chloropyrimidines with alkenylboronic acids readily proceed to give the corresponding alkenylpyrimidines in high to excellent yields. The coupling reaction of 2,4-dichloropyrimidine or 2,4,6-trichloropyrimidine with one equivalent of alkenylboronic acid occurred more easily on 4-position than on 2-position, which implied that the reaction is highly regioselective. The reaction is stereospecific since the configu-ration of C=C remained intact. The preliminary study on the cross-coupling reactions of 2,4,6-trichlorotriazine with one equivalent of arylboronic acids showed that the reactions afforded the monosubstituted triazines in moder-ate yields. The effect of steric hindrance of the substitutents on the reactions was found.展开更多
The reactions of trialkylalkynylborate with many electrophiles, as the effective method, appear to have a broader and broader prospect in organic synthesis. In the presence of palladium complex, trialkylalkynylborate ...The reactions of trialkylalkynylborate with many electrophiles, as the effective method, appear to have a broader and broader prospect in organic synthesis. In the presence of palladium complex, trialkylalkynylborate can be allylated by allyl acetate, after protonation, giving 1, 4-alkadienes with high stereoselectivity. Similarly, the reaction between展开更多
基金the National Defense Industry Foundation (No. BZJ030901) and the Science and Technology Foundation of the National De-fense Key Laboratory of Propellant and Explosive Combustion of China (No. 51455010).
文摘The thermal decomposition behavior and kinetic parameters of the exothermic decomposition reactions of the title compound in a temperature-programmed mode have been investigated by means of DSC, TG-DTG and lower rate thermolysis/FTIR. The possible reaction mechanism was proposed. The critical temperature of thermal explo-sion was calculated. The influence of the title compound on the combustion characteristic of composite modified double base propellant containing RDX has been explored with the strand burner. The results show that the kinetic model function in differential form, apparent activation energy Ea and pre-exponential factor A of the major exo-thermic decomposition reaction are 1-a, 207.98 kJmol-1 and 1015.64 s-1, respectively. The critical temperature of thermal explosion of the compound is 312.87 ℃. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as: ()416.422.502?d101 edTTaa-10=-. As an auxiliary catalyst, the title compound can help the main catalyst lead salt of 4-hydroxy-3,5-dinitropyridine oxide to en-hance the burning rate and reduce the pressure exponent of RDX-CMDB propellant.
基金the National Natural Science Foundation of China (No. 20272073).
文摘Pd-catalyzed cross-coupling reactions of chloropyrimidines with alkenylboronic acids readily proceed to give the corresponding alkenylpyrimidines in high to excellent yields. The coupling reaction of 2,4-dichloropyrimidine or 2,4,6-trichloropyrimidine with one equivalent of alkenylboronic acid occurred more easily on 4-position than on 2-position, which implied that the reaction is highly regioselective. The reaction is stereospecific since the configu-ration of C=C remained intact. The preliminary study on the cross-coupling reactions of 2,4,6-trichlorotriazine with one equivalent of arylboronic acids showed that the reactions afforded the monosubstituted triazines in moder-ate yields. The effect of steric hindrance of the substitutents on the reactions was found.
基金Project supported by the National Natural Science Foundation of China.
文摘The reactions of trialkylalkynylborate with many electrophiles, as the effective method, appear to have a broader and broader prospect in organic synthesis. In the presence of palladium complex, trialkylalkynylborate can be allylated by allyl acetate, after protonation, giving 1, 4-alkadienes with high stereoselectivity. Similarly, the reaction between
