In(OTf)3 plays the role of a Lewis acid catalyst in the Pechmann condensation of phenols with β-ketoesters under solvent-free conditions to give coumarin derivatives. This novel and inexpensive method has advantages ...In(OTf)3 plays the role of a Lewis acid catalyst in the Pechmann condensation of phenols with β-ketoesters under solvent-free conditions to give coumarin derivatives. This novel and inexpensive method has advantages such as short reaction time, excellent product yields, and avoids the use of organic solvents in agreement with green chemistry principles. Catalyst loadings can be as low as 1 mol% to give high yields of the corresponding coumarins at 80 °C. The catalyst can be recovered after the reaction, and reused with only a slight decrease in the yield.展开更多
In this paper,we report the design,synthesis and semiconducting behavior of two conjugated D-A polymers BPDDTE and BPDBDTE which entail BPD,a Pechmann dye framework,as electron accepting moieties and(E)-1,2-di(thiophe...In this paper,we report the design,synthesis and semiconducting behavior of two conjugated D-A polymers BPDDTE and BPDBDTE which entail BPD,a Pechmann dye framework,as electron accepting moieties and(E)-1,2-di(thiophen-2-yl)ethane with and without alkyl chains as electron donating moieties.They both show very narrow bandgaps below 1.3 eV.Based on the characterization of the field-effect transistors,thin film of BPDDT exhibits ambipolar semiconducting properties with hole and electron mobilities reaching 0.245 and 0.095 cm^(2)•V^(−1)•s^(−1),respectively,after thermal annealing.Similarly,BPDBDTE with more alkylchains shows ambipolar semiconducting behavior with hole mobility and electron mobilities reaching 0.109 and 0.081 cm^(2)•V^(−1)•s^(−1).Furthermore,BPDBDTE shows good solubilities in several common organic solvents and thus is easily solution-processible.Thus,BPDBDTE is potentially processible with inkjet printing and roll-to-roll printing techniques.展开更多
In order to obtain coumarin derivatives with activities against HIV,six compounds were designed and synthesized by Pechmann condensation reaction.Their structures were confirmed by IR,EA and 1HNMR.
文摘In(OTf)3 plays the role of a Lewis acid catalyst in the Pechmann condensation of phenols with β-ketoesters under solvent-free conditions to give coumarin derivatives. This novel and inexpensive method has advantages such as short reaction time, excellent product yields, and avoids the use of organic solvents in agreement with green chemistry principles. Catalyst loadings can be as low as 1 mol% to give high yields of the corresponding coumarins at 80 °C. The catalyst can be recovered after the reaction, and reused with only a slight decrease in the yield.
基金The present research was financially supported by Chinese Academy of Sciences,NSFC(No.21372226)and State Key Basic Research Program.
文摘In this paper,we report the design,synthesis and semiconducting behavior of two conjugated D-A polymers BPDDTE and BPDBDTE which entail BPD,a Pechmann dye framework,as electron accepting moieties and(E)-1,2-di(thiophen-2-yl)ethane with and without alkyl chains as electron donating moieties.They both show very narrow bandgaps below 1.3 eV.Based on the characterization of the field-effect transistors,thin film of BPDDT exhibits ambipolar semiconducting properties with hole and electron mobilities reaching 0.245 and 0.095 cm^(2)•V^(−1)•s^(−1),respectively,after thermal annealing.Similarly,BPDBDTE with more alkylchains shows ambipolar semiconducting behavior with hole mobility and electron mobilities reaching 0.109 and 0.081 cm^(2)•V^(−1)•s^(−1).Furthermore,BPDBDTE shows good solubilities in several common organic solvents and thus is easily solution-processible.Thus,BPDBDTE is potentially processible with inkjet printing and roll-to-roll printing techniques.
文摘In order to obtain coumarin derivatives with activities against HIV,six compounds were designed and synthesized by Pechmann condensation reaction.Their structures were confirmed by IR,EA and 1HNMR.
