title: Cyclization of oxa-bicyclic alkenes with beta-iodo-(Z)-propenoates and o-iodobenzoate catalyzed by nickel complexes: a simple efficient route to annulated coumarins.
abstract: In the presence of Ni(dppe)Br(2) and Zn powder in acetonitrile at 80 degrees C, oxa-bicyclic olefins undergo cyclization with o-iodobenzoate and with beta-iodo-(Z)-propenoates to give the benzocoumarin derivatives in moderate to good yields. This methodology offers a simple efficient way for the synthesis of structurally complicate coumarins in one pot. [reaction: see text]
authors.affiliation: Department of Chemistry, Tsing Hua University, Hsinchu 300, Taiwan.
authors.forename: Dinesh Kumar
authors.initials: DK
authors.lastname: Rayabarapu
authors.forename: Paritosh
authors.initials: P
authors.lastname: Shukla
authors.forename: Chien-Hong
authors.initials: CH
authors.lastname: Cheng