Highly Diastereo- and Enantioselective Cu-Catalyzed [3 + 3] Cycloaddition of Propargyl Esters with Cyclic Enamines toward Chiral Bicyclo[<i>n</i>.3.1] Frameworks
作者:Cheng Zhang、Xin-Hu Hu、Ya-Hui Wang、Zhuo Zheng、Jie Xu、Xiang-Ping Hu
DOI:10.1021/ja303129s
日期:2012.6.13
Cu-catalyzed asymmetric [3 + 3] cycloaddition of propargyl esters with cyclic enamines is reported. With a combination of Cu(OAc)(2)·H(2)O and a chiral tridentate ferrocenyl-P,N,N ligand as the catalyst, perfect endo selectivities (endo/exo > 98/2) and excellent enantioselectivities (up to 98% ee) for endo cycloadducts were achieved under mild conditions. This method provides a simple and efficient approach
报道了一种新的 Cu 催化的炔丙酯与环状烯胺的不对称 [3 + 3] 环加成反应。结合 Cu(OAc)(2)·H(2)O 和手性三齿二茂铁-P,N,N 配体作为催化剂,完美的内向选择性 (endo/exo > 98/2) 和出色的对映选择性 (up内环加合物达到 98% ee) 在温和条件下实现。该方法为合成光学活性双环[n.3.1]骨架提供了一种简单有效的方法。