Silica-bonded 5-n-propyl-octahydro-pyrimido[1,2-a]azepinium chloride (SB-DBU)Cl as a highly efficient, heterogeneous and recyclable silica-supported ionic liquid catalyst for the synthesis of benzo[b]pyran, bis(benzo[b]pyran) and spiro-pyran derivatives
The reaction of 3-chloropropyl silica (SilprCl) with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in dry acetone affords silica-bonded 5-n-propyl-octahydro-pyrimido[1,2-a]azepinium chloride (SB-DBU)Cl as a new silica-supported ionicliquid catalyst. Afterward, (SB-DBU)Cl is used for the efficientsynthesis of 4H-benzo[b]pyran derivatives via the one-pot, three-componentreaction of carbonyl compounds (cyclohexane-1
3-氯丙基二氧化硅(SilprCl)与1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)在干燥的丙酮中的反应得到二氧化硅键合的5-正丙基-八氢-嘧啶基[1,2- a]氯化ze嗪(SB-DBU)Cl作为新型的二氧化硅负载型离子液体催化剂。之后,(SB-DBU)Cl通过羰基化合物(环己烷-1,3-二酮,5,5-一锅法)的三锅法有效合成4 H-苯并[ b ]吡喃衍生物。(1,3-二甲基环己烷-1,3-二酮或3-甲基-1-苯基-2-吡唑啉-5-酮)与芳族醛和烷基丙二酸酯。此外,一些新颖的双(苯并[ b使用(SB-DBU)Cl合成[] pyran] s和在结构上含有羟吲哚和/或喹喔啉部分的多种结构多样的螺-吡喃。将催化剂循环使用十五次,收率不变。
Improvement in nanocomposite host (nanocavity of dealuminated zeolite Y)-guest (12-molybdophosphoric acid) catalytic activity and its application to the one-pot three-component synthesis of tetrahydrobenzo[ b ]pyrans
efficient chemoselective synthesis of tetrahydrobenzo[b]pyran derivatives, and the corresponding products were obtained in good to excellent yields in very short reaction times. Furthermore, the catalytic activity of this new catalyst in the synthesis of tetrahydrobenzo[b]pyrans was compared with MPA encapsulated in zeolite Y dealuminated by the hydrothermal method. The catalyst (MPA–MDAZY) was recovered
摘要 采用化学方法(乙二胺四乙酸)对沸石 Y 进行脱铝,以修饰沸石结构,以负载 12-磷酸钼酸 (MPA)。MPA 封装在改性脱铝沸石 Y (MDAZY) 的纳米腔中,并通过傅里叶变换红外、X 射线衍射和原子吸收光谱进行表征。新催化剂用于四氢苯并[b]吡喃衍生物的高效化学选择性合成,并在很短的反应时间内以良好至极好的收率获得了相应的产物。此外,将这种新催化剂在四氢苯并[b]吡喃合成中的催化活性与包封在通过水热法脱铝的沸石Y中的MPA进行了比较。
Glycerol as a biodegradable and reusable promoting medium for the catalyst-free one-pot three component synthesis of 4H-pyrans
Glycerol is applied as a green, biodegradable and reusable promoting medium for one-pot three component synthesis of 4H-pyrans under catalyst-free conditions. A broad range of substrates including aromatic and heteroaromatic aldehydes, isatine derivatives, acenaphthenequinone and ninehydrine are condensed with carbonyl compounds possessing a reactive α-methylene group and alkylmalonates. All reactions are completed in short times, and the products are obtained in good to excellent yields. The reaction medium could be recycled and reused several times without any loss of efficiency.
Silica bonded n-propyl-4-aza-1-azoniabicyclo[2.2.2]octane chloride (SB-DABCO): A highly efficient, reusable and new heterogeneous catalyst for the synthesis of 4H-benzo[b]pyran derivatives
3-chloropropyl silica with diazabicyclo[2.2.2]octane in dry acetone affords silica bonded n-propyl-4-aza-1-azoniabicyclo[2.2.2]octane chloride (SB-DABCO) as a new basic catalyst. The catalyst is used for the efficientsynthesis of 4H-benzo[b]pyranderivatives via one-pot three-component reaction of cyclic ketones/1,3-diketones with aromatic aldehydes and alkylmalonates.
3-氯丙基二氧化硅与二氮杂双环[2.2.2]辛烷在干燥丙酮中的反应提供了与二氧化硅键合的正丙基-4-氮杂-1-氮杂双环[2.2.2]辛烷氯化物(SB-DABCO),作为一种新的碱性催化剂。通过环酮/ 1,3-二酮与芳族醛和丙二酸烷基酯的一锅三组分反应,该催化剂可用于高效合成4 H-苯并[ b ]吡喃衍生物。
A green one-pot three-component synthesis of tetrahydrobenzo[b]pyran and 3,4-dihydropyrano[c]chromene derivatives using a Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>–imid–PMA<sup>n</sup> magnetic nanocatalyst under ultrasonic irradiation or reflux conditions
An efficient and environmentallybenign procedure for the synthesis of tetrahydrobenzo[b]pyran and 3,4-dihydropyrano[c]chromene derivatives has been developed by a one-pot three-component reaction of various aldehydes, malononitrile, and dimedone or hydroxycoumarin in the presence of Fe3O4@SiO2–imid–PMAn nanoparticles as magnetic catalysts under ultrasonic irradiation or reflux conditions in water
通过在锅中各种醛,丙二腈,二甲酮或羟基香豆素的一锅三组分反应,开发了一种有效的,对环境无害的合成四氢苯并[ b ]吡喃和3,4-二氢吡喃并[ c ]色烯衍生物的方法。 Fe 3 O 4 @SiO 2-亚胺基-PMA n的存在超声辐射或水中回流条件下,纳米颗粒作为磁性催化剂。该新方法具有显着的优点,例如操作简单,产率高,反应时间短以及无需任何繁琐的后处理或纯化。另外,在水介质中的优异催化性能以及催化剂的易于制备,热稳定性和分离使其成为良好的非均相体系,并且是其他非均相催化剂的有用替代品。同样,该催化剂可以很容易地通过磁场回收并在连续的八个反应循环中重复使用而没有明显的活性损失。