An Evidence for Remarkable Difference of the Electrophilicity between Two Carbonyl Groups in the Photoexcited 1,2-Naphthoquinone. Photocycloaddition Reaction of 1,2-Naphthoquinone with Olefins
作者:Akio Takuwa
DOI:10.1246/cl.1989.5
日期:1989.1
The [4+2]photocycloaddition reactions between 1,2-naphthoquinone and olefins have been investigated. From the results of the stereochemistry and the regiochemistry of the adducts, it is concluded that the carbonyl oxygen atom at the position 2 in the photoexcited triplet state of 1,2-naphthoquinone attacks selectively one of the olefinic carbons.
Cu<sub>2</sub>O-Catalyzed Tandem Ring-Opening/Coupling Cyclization Process for the Synthesis of 2,3-Dihydro-1,4-benzodioxins
作者:Weiliang Bao、Yunyun Liu、Xin Lv、Weixing Qian
DOI:10.1021/ol801444p
日期:2008.9.1
2, 3-Dihydro-1,4-benzodioxins can be prepared in a tandem one-pot procedure by reaction of o-iodophenols with epoxides catalyzed by Cu2O/1,10-phenanthroline/Cs2CO3 system. The reaction is suggested to occur via a novel ring-opening/coupling mechanism, giving moderate to good yields. Moreover, both aryl and aliphatic epoxides are tolerated under these conditions.