Friedel–Crafts alkylation between chalcone epoxides and heteroarenes induced by triarylaminium salt
作者:Congde Huo、Xiaolan Xu、Xiaodong Jia、Xicun Wang、Jinzhu An、Chougu Sun
DOI:10.1016/j.tet.2011.10.062
日期:2012.1
Triarylaminiumsalt was disclosed as a highly efficient nonmetallic initiator for the Friedel–Crafts reaction between chalcone epoxides and heteroarenes to construct a series of complex β-heteroaryl α-ketols in mild conditions and with good yields. Chalcone epoxides were presented as valuable halogen-free pre-electrophile in Friedel–Crafts alkylation through the formation of the stabilized benzylic
The Kinetics of the Darzens Reaction of<i>p</i>-Substituted Benzaldehydes and Phenacyl Chloride
作者:Raj Kumar Bansal、Kanta Sethi
DOI:10.1246/bcsj.53.1197
日期:1980.4
The rate constants for the base-catalyzed Darzens reaction of p-substituted benzaldehydes and phenacyl chloride have been measured at two temperatures in aqueous dioxane. Enthalpies and entropies of activation have been evaluated. The reactivity of the p-substituted benzaldehydes was found to follow the order p-NO2>p-Cl>p-Br>H>p-CH3>p-OCH3. The kinetic data can be correlated with ρ values according
Visible-light-induced epoxidation of α,β-unsaturatedketones is a kind of important chemical transformations, which could be applied for the synthesis of epoxypropane derivatives. Here, an efficient aerobic photoepoxidation protocol was reported. Through decatungstate-mediated photocatalysis, the aerobic Epoxidations of α,β-unsaturatedketones proceed well, furnishing the desired product in moderate