1856-63-9Relevant articles and documents
Easy access to (E) β-ocimene
Yildizhan, Selma,Schulz, Stefan
, p. 2831 - 2833 (2011)
β-Ocimene is one of the most common monoterpenes found in Nature, but a simple and reliable synthesis of the pure E-isomer has been missing. Here, we report a simple procedure involving a Grignard coupling as the key step that allows its synthesis on gram scales. The configuration of the double bond is fixed in the starting material. Georg Thieme Verlag Stuttgart · New York.
Silver nanoparticle-Catalyzed diels-alder cycloadditions of 2′-hydroxychalcones
Cong, Huan,Becker, Clinton F.,Elliott, Sean J.,Grinstaff, Mark W.,Porco Jr., John A.
, p. 7514 - 7518 (2010)
Metal nanoparticles are currently being employed as catalysts for a number of classical chemical transformations. In contrast, identification of novel reactions of nanoparticles, especially toward the synthesis of complex natural products and derivatives, is highly underdeveloped and represents a bourgeoning area in chemical synthesis. Herein, we report silica-supported silver nanoparticles as solid, recyclable catalysts for Diels-Alder cycloadditions of 2′-hydroxychalcones and dienes in high yield and turnover number. The use of silver nanoparticle catalysts is further demonstrated by the total synthesis of the cytotoxic natural product panduratin A employing a highly electron-rich dienophile and Lewis acid sensitive diene.
Frank
, p. 130 (1968)
SnCl2-catalyzed synthesis of carbamates from renewable origin alcohols
da Silva, Márcio José,Chaves, Diego Morais
, p. 1169 - 1180 (2019/01/28)
Effects of structure and reactivity of renewable origin alcohols in the conversion and selectivity of the SnCl2-catalyzed reactions in the presence and absence of urea were assessed. Convenient simple and suitable method for the synthesis of carbamates from renewable origin alcohols and urea in one-step are provided. We have assessed the activity of SnCl2 catalyst, a commercially affordable Lewis acid, in reactions of urea alcoholysis with different natural origin alcohols (geranyl, neryl, bornyl, cinnamyl, α-terpinyl and benzyl alcohols), aiming to synthesize carbamates, which are biologically active compounds, building blocks in organic synthesis and raw material to synthesize polyurethanes. The low cost of urea, the water tolerant catalyst and phosgene free reaction are positive aspects of this carbamates synthesis process. The different reaction pathways were assessed. A mechanism was proposed based on FT-IR experiments and experimental data.
A comparative study on the gas-phase and liquid-phase thermal isomerization reaction of α-pinene
He, Jindong,Gong, Yan,Zhao, Wentao,Tang, Xiangyang,Qi, Xin
, p. 15 - 22 (2013/03/13)
In this paper, a method of preparation of ocimene is investigated, which is obtained from isomerization reaction of α-pinene. Two kinds of experimental apparatus are established for the investigation of the thermal isomerization reaction of α-pinene. The behavior of thermal isomerization reaction of α-pinene is respectively discussed in the gas phase and in the liquid phase. Under gas phase conditions, the conversion of α-pinene is 80% and the selectivity of ocimene is 30%-33%. Under liquid phase conditions, the conversion of α-pinene is 60% and the selectivity of ocimene is 50%-54%. According to the kinetic-molecular theory of ideal gases, two kinds of reaction models are proposed to visualize the reaction process. In addition, the mechanism and kinetics of thermal isomerization reaction of α-pinene are respectively discussed. The conclusion is that the gas phase reaction temperature is calculated to be 390-450 °C and the liquid phase reaction temperature is calculated to be 450-550°C. From a bond dissociation energy point of view, results support the hypothesis that the reaction involves biradical intermediates. Copyright
