Tsuchikama Kyoji, Kuwata Yusuke, Shibata Takanori
Department of Chemistry, School of Science and Engineering, Waseda University, Shinjuku, Tokyo, 169-8555, Japan.
J Am Chem Soc. 2006 Oct 25;128(42):13686-7. doi: 10.1021/ja064257u.
The enantioselective [2 + 2 + 2] cycloaddition of 1,6-diynes with alpha-methylene lactones and cyclic ketones gave various chiral spirocyclic compounds. The reaction proceeded with high enantioselectivity when the rhodium-xylylBINAP complex was used as a chiral catalyst. Not only exo-methylene cyclic compounds but also exo-methylene acyclic compounds could be used as coupling partners for diynes. The present protocol provides access to a new chiral library possessing a quaternary carbon center, including a spirocyclic system.
1,6 - 二炔与α - 亚甲基内酯和环状酮的对映选择性[2 + 2 + 2]环加成反应生成了各种手性螺环化合物。当使用铑 - 二甲苯基联萘磷配合物作为手性催化剂时，该反应以高对映选择性进行。不仅外亚甲基环状化合物，而且外亚甲基非环状化合物都可以用作二炔的偶联伙伴。本方法提供了一种获取具有季碳中心的新手性库的途径，该手性库包括一个螺环体系。
