Aryl-2,2′-bipyridine was obtained by means of the annulation reaction of ammonia and the addition product of each of β-arylvinamidinium salts with 2-acetyl pyridine. The annulation reaction was dependent on the natu...Aryl-2,2′-bipyridine was obtained by means of the annulation reaction of ammonia and the addition product of each of β-arylvinamidinium salts with 2-acetyl pyridine. The annulation reaction was dependent on the nature of the substituent at the β-position of the vinamidinium species.展开更多
This paper reports the results on the nature of bond-order and net charge distributions predicted by Ab initio Hartree- Fock procedures for 1-amino-2-iminio-, 1-amino-3-iminio- and 1-amino-4-iminiotropylium cations th...This paper reports the results on the nature of bond-order and net charge distributions predicted by Ab initio Hartree- Fock procedures for 1-amino-2-iminio-, 1-amino-3-iminio- and 1-amino-4-iminiotropylium cations that incorporate, in order, the 1,7-, 1,3- and 1,5-diazapentadienium (vinamidinium) elements. There appears to be very little contribution from tropylium-type charge distribution, the positive charges residing largely in the nitrogen atoms. The partial bond fixations and charge distributions show interesting variation in the three isomers. The 1,3-isomer in which the 1,3-diazapentadienium element is preserved in the favoured zigzag conformation appears to be relatively the best stabilized. The six isomeric benzo-fused derivatives arising from the three amino-iminiotropylium cations show similar differences in patterns of behaviour. Interestingly, the isomer in which a zigzag 1,3-diazapentadienium element is conjugated with a styrene moiety receives the deepest stabilization. While showing that the element largely contributes to the relative stabilization among the systems studied, contribution from certain stereochemical destabilizing factors may not be insignificant.展开更多
A variety of vinamidinium salts were condensated with cyanoacetamide in refluxing methanol that contained sodium methoxide to produce 5-aryl-3-cyano-2-pyridones in good yield. Simple experimental conditions were used ...A variety of vinamidinium salts were condensated with cyanoacetamide in refluxing methanol that contained sodium methoxide to produce 5-aryl-3-cyano-2-pyridones in good yield. Simple experimental conditions were used to prepare ten different 5-aryl-3- cyano-2-pyridones, four of which are new compounds.C 2009 Song Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
目的:研究2-甲氧羰基-4-芳基噻吩衍生物的合成工艺。方法:以相应的芳基乙酸为原料在V ilsm e ir-Haack条件下制备V inam id in ium盐,在甲醇钠-甲醇碱性溶剂体系与巯基乙酸甲酯回流,制备2-甲氧羰基-4-芳基噻吩衍生物。结果:合成了10个...目的:研究2-甲氧羰基-4-芳基噻吩衍生物的合成工艺。方法:以相应的芳基乙酸为原料在V ilsm e ir-Haack条件下制备V inam id in ium盐,在甲醇钠-甲醇碱性溶剂体系与巯基乙酸甲酯回流,制备2-甲氧羰基-4-芳基噻吩衍生物。结果:合成了10个目标化合物,其中5个为新化合物。化合物结构经核磁共振氢谱和高分辨质谱确证。结论:发现一个新的2-甲氧羰基-4-芳基噻吩衍生物的合成方法,反应条件温和,操作简单,收率高,并提出了可能的反应机制。展开更多
文摘Aryl-2,2′-bipyridine was obtained by means of the annulation reaction of ammonia and the addition product of each of β-arylvinamidinium salts with 2-acetyl pyridine. The annulation reaction was dependent on the nature of the substituent at the β-position of the vinamidinium species.
文摘This paper reports the results on the nature of bond-order and net charge distributions predicted by Ab initio Hartree- Fock procedures for 1-amino-2-iminio-, 1-amino-3-iminio- and 1-amino-4-iminiotropylium cations that incorporate, in order, the 1,7-, 1,3- and 1,5-diazapentadienium (vinamidinium) elements. There appears to be very little contribution from tropylium-type charge distribution, the positive charges residing largely in the nitrogen atoms. The partial bond fixations and charge distributions show interesting variation in the three isomers. The 1,3-isomer in which the 1,3-diazapentadienium element is preserved in the favoured zigzag conformation appears to be relatively the best stabilized. The six isomeric benzo-fused derivatives arising from the three amino-iminiotropylium cations show similar differences in patterns of behaviour. Interestingly, the isomer in which a zigzag 1,3-diazapentadienium element is conjugated with a styrene moiety receives the deepest stabilization. While showing that the element largely contributes to the relative stabilization among the systems studied, contribution from certain stereochemical destabilizing factors may not be insignificant.
基金supported by the National Basic Research Program of China(No.2004CB518908)the National High Technology Research and Development Program of China(No.2006AA020601).
文摘A variety of vinamidinium salts were condensated with cyanoacetamide in refluxing methanol that contained sodium methoxide to produce 5-aryl-3-cyano-2-pyridones in good yield. Simple experimental conditions were used to prepare ten different 5-aryl-3- cyano-2-pyridones, four of which are new compounds.C 2009 Song Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘目的:研究2-甲氧羰基-4-芳基噻吩衍生物的合成工艺。方法:以相应的芳基乙酸为原料在V ilsm e ir-Haack条件下制备V inam id in ium盐,在甲醇钠-甲醇碱性溶剂体系与巯基乙酸甲酯回流,制备2-甲氧羰基-4-芳基噻吩衍生物。结果:合成了10个目标化合物,其中5个为新化合物。化合物结构经核磁共振氢谱和高分辨质谱确证。结论:发现一个新的2-甲氧羰基-4-芳基噻吩衍生物的合成方法,反应条件温和,操作简单,收率高,并提出了可能的反应机制。
