Synthesis of C1-Substituted Oxabenzonorbornadienes
摘要:
Oxabenzonorbornadienes are valuable synthetic intermediates because they can serve as a general template with which to create highly substituted ring systems. However, to date, only very few C1-substituted oxabenzonorbornadienes have been reported. In this study, the synthesis of some C1-substituted oxabenzonorbornadienes was achieved by the Diels-Alder reaction between 2-substituted furans and benzyne. Moderate to good yields (16-80%) of the Diels-Alder reactions were observed. These C1-substituted oxabenzonorbornadienes will find applications as valuable synthetic intermediates and should be useful in studies of transition-metal-catalyzed reactions.
synthesis of 2-substitutedfurans via palladium- and iron-catalyzed coupling utilizing 2-bromofuran is described. Whereas palladium-catalyzed Suzuki coupling effectively provided the corresponding aryl furans, little or no product was obtained by palladium-catalyzed coupling with various alkyl nucleophiles. Iron-catalyzed coupling proved effective for the synthesis of primary and secondary alkyl furans in modest