Transition-metal-free selective pyrimidines and pyridines formation from aromatic ketones, aldehydes and ammonium salts
作者:Jinjin Chen、Huanxin Meng、Feng Zhang、Fuhong Xiao、Guo-Jun Deng
DOI:10.1039/c9gc02077b
日期:——
An efficient synthesis of pyrimidines and pyridines has been developed from readily available aromaticketones, aldehydes and ammonium salts under transition-metal-free conditions. In this strategy, ammonium salts were used as nitrogen sources and only water was generated as a nontoxic byproduct. A catalytic amount of NaIO4 played an important role in the selectivity control, whereas substituted pyridines
An Efficient Synthesis of 2,4,6-Triarylpyridines by Use of Benzyl Halides under Neat Conditions
作者:Mehdi Adib、Neda Ayashi、Peiman Mirzaei
DOI:10.1055/s-0035-1560365
日期:——
An efficient synthesis of 2,4,6-triarylpyridines is described. Heating a mixture of an acetophenone, a benzyl halide, and ammonium acetate under neat conditions afforded the corresponding Krohnke pyridines in excellent yields.
Silica vanadic acid [SiO<sub>2</sub>–VO(OH)<sub>2</sub>] as an efficient heterogeneous catalyst for the synthesis of 1,2-dihydro-1-aryl-3H-naphth[1,2-e][1,3]oxazin-3-one and 2,4,6-triarylpyridine derivatives via anomeric based oxidation
作者:Mohammad Ali Zolfigol、Maliheh Safaiee、Fatemeh Afsharnadery、Neda Bahrami-Nejad、Saeed Baghery、Sadegh Salehzadeh、Farahnaz Maleki
DOI:10.1039/c5ra21392d
日期:——
efficiently catalyzed the synthesis of 1,2-dihydro-1-aryl-3H-naphth[1,2-e][1,3]oxazin-3-ones via reacting aromatic aldehydes and β-naphthol and urea undersolvent-freecondition. Additionally, 2,4,6-triarylpyridine derivatives were prepared through the condensation of ammonium acetate, aromatic aldehyde and various acetophenone in the presence of a catalytic amount of [SiO2–VO(OH)2] (SVA) under a same condition
二氧化硅键合的钒酸[SiO 2 -VO(OH)2 ](SVA)有效催化1,2-二氢-1-芳基-3 H-萘[1,2- e ] [1,3]恶嗪的合成通过在无溶剂条件下使芳族醛与β-萘酚和尿素反应生成-3-酮。另外,在催化量的[SiO 2 -VO(OH)2的存在下,通过乙酸铵,芳族醛和各种苯乙酮的缩合反应制备了2,4,6-三芳基吡啶衍生物。](SVA)在相同条件下。为2,4,6-三芳基吡啶衍生物的合成的最后一步提出了一种新的基于端基的氧化方法,这一方法得到了理论研究的支持。因此,在合理设计,合成和应用新型氢化物释放化合物的过程中,所描述的新机理可以开辟新的前景。本方法的显着特征是反应时间短,产率高,后处理容易和SVA催化剂的可回收性。
An Efficient Improve for the Kröhnke Reaction: One-pot Synthesis of 2,4,6-Triarylpyridines Using Raw Materials under Microwave Irradiation
A series of 2,4,6-triarylpyridines have been prepared by the one-pot reaction of aldehydes with aromatic ketones in the presence of ammonium acetate undermicrowaveirradiation without catalyst. This method has the advantage of easier workup, shorter reaction time, higher yield, and environment-friendly.
A simple and benign protocol has been explored for the preparation of 2,4,6-triarylpyridines by a one-pot reaction between aryl aldehydes, enolizable ketones and ammonium acetate in the presence of N-bromosuccinimide or trichloroisocyanuric acid as green and neutral catalysts. The reactions proceed smoothly at 130 °C under solvent-free conditions to provide 2,4,6-triarylpyridines in good yields.