devices designed for a specific type of reaction were used mainly for highly exothermic, very fast reactions. Described is a modular microreaction system and its application to representative homogeneous and heterogeneous reactions important in organic synthesis. The modular microreaction system allows continuous flow processes to be optimized and employed effectively in the chemical laboratory. The modular
calcination of the Sn–W hydroxide at 800 °C acts as an effective and reusable solid catalyst for CCbond‐formingreactions, such as the cyclization of citronellal, the Diels–Alder reaction, and the cyanosilylation of carbonyl compounds with trimethylsilyl cyanide (see scheme). The observed catalysis was truly heterogeneous, and the recovered catalyst could be reused without loss of its high catalytic performance
Monomeric Metal Aqua Complexes in the Interlayer Space of Montmorillonites as Strong Lewis Acid Catalysts for Heterogeneous Carbon-Carbon Bond-Forming Reactions
scandium catalysts (Cu(2+)- and Sc(3+)-monts) were easily prepared by treating Na(+)-mont with the aqueous solution of the copper nitrate and scandium triflate, respectively. The resulting Cu(2+)- and Sc(3+)-monts showed outstanding catalytic activities for a variety of carbon-carbonbond-formingreactions, such as the Michael reaction, the Sakurai-Hosomi allylation, and the Diels-Alder reaction, under
Synthesis and Physicochemical Properties of Strong Electron Acceptor 14,14,15,15-Tetracyano-6,13-pentacenequinodimethane (TCPQ) Diimide
作者:Jie Li、Yu Xiong、Qinghe Wu、Shitao Wang、Xike Gao、Hongxiang Li
DOI:10.1002/ejoc.201201065
日期:2012.11
14,14,15,15-Tetracyano-6,13-pentacenequinodimethane (TCPQ) diimide, a new tetracyanoquinodimethane analogue with extended conjugation and imide substituents, was synthesized by double Diels–Alder reactions and a Knoevenagel condensation reaction. Experimental results showed that TCPQ diimide has a low LUMO energy level (–4.03 eV) and good solubility in organic solvents.
Solvent-Free Diels–Alder Reaction in a Closed Batch System
作者:Daolai Sun、Fumiya Sato、Yasuhiro Yamada、Satoshi Sato
DOI:10.1246/bcsj.20120247
日期:2013.2.15
Solvent-free Diels–Alder reactions were carried out by heating a mixture of a volatile diene, such as 1,3-butadiene, isoprene, or 2,3-dimethyl-1,3-butadiene, and a dienophile, such as methyl vinyl ketone, methyl acrylate, or maleic anhydride, in a closed batch reactor. High yields of Diels–Alder products were obtained without using solvents and catalysts within a short reaction time in most of the reactions. In particular, several reactions of dienophiles with 1,3-butadiene, which is known as a diene with low reactivity because of its gaseous form, also proceeded with high yields of Diels–Alder products in the closed batch reactor under conditions pressured by the reactant vapor. Solvent-free reactions provided high yields compared to reactions in solvent since the reaction heat directly resulted in increasing the reaction temperature and pressure. Energy in the exothermic reaction was used effectively in the closed batch system under solvent-free conditions.