A metal-free oxidative arene/alkene annulation-aromatization has been realized, which enables efficient synthesis of 2-arylnaphtho[2,1-b]furans from readily available terminalarylalkenes and 2-naphthols. Mechanistic study suggests that this reaction proceeds via free-radical initiated tandem cyclization, dehydrogenative rearomatization and aromatization.
已经实现了无金属的氧化芳烃/烯烃环化-芳香化,其使得能够从容易获得的末端芳基烯烃和2-萘酚有效地合成2-芳基萘[2,1- b ]呋喃。机理研究表明,该反应是通过自由基引发的串联环化,脱氢重新芳构化和芳构化进行的。
Metal-Free Oxidative Annulation of 2-Naphthols with Terminal Alkynes Affording 2-Arylnaphtho[2,1<i>-b</i>]furans
For the first time, the selective oxidative transformation of 2-naphthols with terminal alkynes is disclosed, which enables the straightforward synthesis of 2-arylnaphtho[2,1-b]furans in satisfactory yields under metal-free conditions. Mechanistic study suggests that the reaction proceeds via free-radical-mediated sp2-C–H bond activation, C–C coupling, and C–O cyclization.
首次公开了2-萘酚与末端炔烃的选择性氧化转化,其使得在无金属条件下以令人满意的产率直接合成2-芳基萘[2,1- b ]呋喃成为可能。机理研究表明,该反应通过自由基介导的sp 2 -C–H键激活,CC偶联和CO环化来进行。
Hypervalent Iodine Mediated Oxidative Cyclization of o-Hydroxystilbenes into Benzo- and Naphthofurans
作者:Thomas Wirth、Fateh Singh
DOI:10.1055/s-0031-1290588
日期:2012.4
A new and convenient metal-free cyclization of ortho-hydroxystilbenes into 2-arylbenzofurans and 2-arylnaphthofurans mediated by hypervalent iodine reagents is described. The cyclization products are isolated in good to excellent yields using stoichiometric (diacetoxyiodo)benzene in acetonitrile.
SEEMUTH P. D.; ZIMMER H., J. ORG. CHEM., 1978, 43, NO 15, 3063-3065