Scandium (III)-Catalyzed Cycloaddition of <i>in situ</i>
Generated <i>ortho</i>
-Quinone Methides with Vinyl Azides: An Efficient Access to Substituted 4<i>H</i>
-Chromenes
作者:Nuligonda Thirupathi、Chen-Ho Tung、Zhenghu Xu
DOI:10.1002/adsc.201800565
日期:2018.9.17
convenient and practical synthesis of 4H‐chromenes from the readily accessible o‐hydroxybenzhydryl alcohols and vinyl azides has been achieved. The transformation proceeds through a cascade that involves formation of an ortho‐quinonemethide, [4+2]‐cycloaddition and elimination of hydrazoic acid. The reaction is well tolerated with respect to both the o‐hydroxybenzhydrols and the vinyl azides and affords