A regioselective [3 + 2] cycloaddition of benzofuranone type active olefins with allenoates catalyzed by trivalent phosphines has been developed, which provided an easy access to enriched functionalized spirocyclic benzofuranones. The reactions accommodated a number of benzofuranone type electron-deficient olefins and allenoates to give the desired 3-spirocyclopentane benzofuran-2-ones or 2-spirocyclopentane benzofuran-3-ones with moderate to excellent yields (up to 99%) and moderate to good regioselectivities (up to 11 : 1).
苯并呋喃酮类活性烯烃与烯
丙酸酯在三价膦催化下的区域选择性[3 + 2]环加成反应已经开发出来,这为获得富含官能团的螺环
苯并呋喃酮提供了简便的方法。该反应可容纳多种
苯并呋喃酮类电子缺陷烯烃和烯
丙酸酯,以中等至优异的产率(高达99%)和中等至良好的区域选择性(高达11:1)生成所需的3-螺
环戊烷苯并呋喃-2-酮或2-螺
环戊烷苯并呋喃-3-酮。