Synthesis of 2,5-Disubstituted 3-Iodofurans via Palladium-Catalyzed Coupling and Iodocyclization of Terminal Alkynes
作者:Zhengwang Chen、Gao Huang、Huanfeng Jiang、Huawen Huang、Xiaoyan Pan
DOI:10.1021/jo1023987
日期:2011.2.18
2,5-Disubstituted 3-iodofurans are readily prepared under very mild reaction conditions by the palladium/copper-catalyzed cross-coupling of (Z)-β-bromoenol acetates and terminal alkynes, followed by iodocyclization. The useful intermediates conjugated enyne acetates are obtained in high yields in the transformation. Aryl- and alkyl-substituted alkynes undergo iodocyclization in good yields. The resulting
A highlyefficientsynthesis of a wide range of 2,5-disubstituted furans from enyne acetates is described. The reactions are conducted by using Lewis acid and palladiumcatalyst and provide symmetrical and unsymmetrical products in good to excellent yields, with broad substrate scope, including a variety of aromatic and aliphatic substituents in the 2- and 5-position of the furan ring.