Department of Chemistry and State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin, China.
Org Biomol Chem. 2013 Mar 7;11(9):1451-5. doi: 10.1039/c3ob27288e.
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).
三价膦催化苯并呋喃酮型活性烯烃与丙二烯酸酯的区域选择性[3 + 2]环加成反应已经被开发出来，为丰富的功能化螺环苯并呋喃酮的合成提供了一种简便的方法。该反应能够容纳许多苯并呋喃酮型缺电子烯烃和丙二烯酸酯，以中等至优异的收率（高达 99%）和中等至良好的区域选择性（高达 11:1）得到所需的 3-螺环戊烷苯并呋喃-2-酮或 2-螺环戊烷苯并呋喃-3-酮。
