A Chiral N,N′‐Dioxide–ZnII Complex Catalyzes the Enantioselective [2+2] Cycloaddition of Alkynones with Cyclic Enol Silyl Ethers |
| |
| Authors: | Tengfei Kang Shulin Ge Dr Lili Lin Yan Lu Prof?Dr Xiaohua Liu Prof?Dr Xiaoming Feng |
| |
| Institution: | 1. Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, China;2. Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China |
| |
| Abstract: | A highly efficient enantioselective 2+2] cycloaddition between alkynones and cyclic enol silyl ethers was developed by using a chiral N,N′‐dioxide‐zinc(II) complex as a catalyst. This method functions well for a variety of terminal alkynes as well as cyclic enol silyl ethers, with good to excellent enantioselectivity (up to 97 % ee). This is also the first successful example for the catalytic enantioselective 2+2] cycloaddition of internal alkynes with cyclic enol silyl ethers to give fully substituted cyclobutenes. Meanwhile, the desired cyclobutene product can easily be transformed into fused cyclobutane derivatives. |
| |
| Keywords: | [2+2] cycloaddition asymmetric catalysis cycloaddition N N′ -dioxides synthetic methods |
|
|
