Electrophilic cyclization of 3-alkynyl-4-chalcogen-2-H-chromenes: synthesis of 3-halo-chalcogenophene[3,2-c]chromene derivatives
作者:Adriane Sperança、Benhur Godoi、Michael Daniel Costa、Paulo Henrique Menezes、Gilson Zeni
DOI:10.1016/j.tetlet.2010.11.049
日期:2011.1
accomplished via electrophilic cyclization reaction of 3-alkynyl-4-chalcogen-2H-chromene using I2, PhSeBr, and BuTeBr3 as electrophilic sources. The cyclization reaction proceeded cleanly under mild reaction conditions, and 3-halochalcogen-chromenes were formed in good yields. In addition, the obtained 3-iodo-chalcogenophene-chromenes were readily transformed to more complex products using a metal–halogen exchange
使用I 2,PhSeBr和BuTeBr 3作为亲电源,通过3-炔基-4-硫族元素-2 H-色烯的亲电环化反应,已经完成了3-卤代硫族元素oph [3,2- c ]色烯的高效合成。环化反应在温和的反应条件下进行得很干净,并以良好的收率形成了3-卤代烃-色烯。此外,所获得的使用具有金属-卤素交换反应3-碘chalcogenophene-色烯被容易地转化为更复杂的产品Ñ-BuLi并捕获与醛形成的中间体锂,以高收率提供所需的仲醇。相反,使用钯与末端炔烃和硼酸的交叉偶联反应,我们能够以高收率获得Sonogashira和Suzuki型产品。