The yield and stereoselectivity of the Diels-Alder reactions between furan(or 2-methylfuran)and different dienophiles are markedly enhanced by the catalysis of anhydrous YbCl_3.
An efficient synthesis of tetrahydroquinoline derivatives is reported via three component coupling reactions of aldehydes and anilines with various dienophiles in the presence of a catalytic amount of perchloric acid ...An efficient synthesis of tetrahydroquinoline derivatives is reported via three component coupling reactions of aldehydes and anilines with various dienophiles in the presence of a catalytic amount of perchloric acid adsorbed on silica gel（HClO;-SiO;） under mild reaction conditions.展开更多
2-nitrobenzofuran is studied as dienophile in polar thermal Diels-Alder reactions with normal electron demand using several structurally different dienes. A very strong electron-acceptor group, such as nitro group, en...2-nitrobenzofuran is studied as dienophile in polar thermal Diels-Alder reactions with normal electron demand using several structurally different dienes. A very strong electron-acceptor group, such as nitro group, enhances the dienophilic character of these heterocyclic compounds and owing to the fact that this substituent is easily extruded under thermal conditions this reaction sequence becomes a simple method of organic compound＇s families with heteroatom rings preparation. Part of this work is specifically concerned with theoretical studies. The global and local electrophilicity and nucleophilicity indexes were calculated for the dienophile and dienes used in this work. A concise synthesis of dibenzofurans has been development via cycloaddition reactions.展开更多
文摘The yield and stereoselectivity of the Diels-Alder reactions between furan(or 2-methylfuran)and different dienophiles are markedly enhanced by the catalysis of anhydrous YbCl_3.
基金Department of Science and Technology,India(No.SR/FT/CS-019/2008) for their financial support
文摘An efficient synthesis of tetrahydroquinoline derivatives is reported via three component coupling reactions of aldehydes and anilines with various dienophiles in the presence of a catalytic amount of perchloric acid adsorbed on silica gel（HClO;-SiO;） under mild reaction conditions.
文摘2-nitrobenzofuran is studied as dienophile in polar thermal Diels-Alder reactions with normal electron demand using several structurally different dienes. A very strong electron-acceptor group, such as nitro group, enhances the dienophilic character of these heterocyclic compounds and owing to the fact that this substituent is easily extruded under thermal conditions this reaction sequence becomes a simple method of organic compound＇s families with heteroatom rings preparation. Part of this work is specifically concerned with theoretical studies. The global and local electrophilicity and nucleophilicity indexes were calculated for the dienophile and dienes used in this work. A concise synthesis of dibenzofurans has been development via cycloaddition reactions.
