18989-35-0Relevant articles and documents
Synthesis of lithium/cesium-Zagronas from zagrosian natural asphalt and study of their activity as novel, green, heterogeneous and homogeneous nanocatalysts in the Claisen–Schmidt and Knoevenagel condensations
Soleiman-Beigi, Mohammad,Ghalavand, Saba,Venovel, Hadis Gholami,Kohzadi, Homa
, p. 3267 - 3279 (2021/06/17)
A novel, heterogeneous and homogeneous basic nanocatalysts were synthesized by grafting of lithium and cesium on zagrosian natural asphalt sulfonate (Li/Cs-Zagronas). The activity of these catalysts was examined in the Claisen–Schmidt and Knoevenagel condensations under mild reaction conditions. Li/Cs-Zagronas were characterized by FT-IR spectroscopy, scanning electron microscopy, X-ray diffraction, energy-dispersive spectroscopy, inductively coupled plasma and thermogravimetric analysis techniques. These nanocatalysts were removed by simple filtration and reused several times without any deterioration of activity.
Potassium Natural Asphalt Sulfonate (K-NAS): Synthesis and characterization as a new recyclable solid basic nanocatalyst and its application in the formation of carbon–carbon bonds
Falah, Saeid,Soleiman-Beigi, Mohammad,Kohzadi, Homa
, (2020/07/06)
In this research, we synthesized and characterized a new heterogeneous basic nanocatalyst and its catalytic application was studied in the Claisen-Schmidt and Knoevenagel condensations. In order to prepare this nanocatalyst, first, the Iranian natural asphalt was sulfonated with the concentrated sulfuric acid and then, converted to the potassium natural asphalt sulfonate (K-NAS). In order to characterization of the nanocatalyst, used of FT-IR spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), inductively coupled plasma (ICP) and thermogravimetric analysis (TGA) techniques. This new basic heterogeneous nanocatalyst have advantages such as being eco-friendly, huge specific surface area, high reactivity and recyclability.
Sulfonated PEG-intercalated montmorillonite [(Mt/PEG)-SO3H] as efficient and ecofriendly nanocatalyst for synthesis of α,α′-bis(substituted benzylidene)cycloalkanones
Dalil Heirati, Seyedeh Zahra,Shirini, Farhad,Fallah Shojaei, Abdollah
, p. 6167 - 6186 (2017/10/05)
(Montmorillonite/PEG)-SO3H nanocomposite was successfully prepared for the first time and introduced as a solid acid nanocatalyst. Initially, polyethylene glycol (PEG) polymeric chains were intercalated into interlayer spaces of montmorillonite. The resulting Mt/PEG nanocomposite with good mechanical and thermal stability was chosen as a useful clay mineral/polymer support for further modification with chlorosulfonic acid. Structural characterization of (Mt/PEG)-SO3H was carried out using X-ray diffraction (XRD) analysis, Brunauer–Emmett–Teller (BET) measurements, Barrett–Joyner–Halenda (BJH) analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier-transform infrared (FT-IR) spectroscopy. The results showed that PEG chains were intercalated into the clay mineral layers and that the Mt/PEG nanocomposite was successfully sulfonated. (Mt/PEG)-SO3H nanocomposite exhibited high specific surface area and good stability up to around 150?°C, showing excellent potential for application as a recyclable nanocatalyst. (Mt/PEG)-SO3H was used as an efficient and ecofriendly solid acid nanocatalyst for preparation of α,α′-bis(substituted benzylidene)cycloalkanones under solvent-free conditions, leading to many interesting findings. The excellent conversion values confirm that the catalyst has strong and sufficient acidic sites, which are responsible for its catalytic performance. The reaction under mild conditions (room temperature) with excellent yield, catalyst recyclability (up to ten times), and simple work-up procedure represent useful advantages of (Mt/PEG)-SO3H for catalysis. Moreover, the reaction could be scaled up to 10 and 15?mmol scales.
