Xu Changming, Qi Yinsheng, Yang Xinshuang, Li Xiangfan, Li Zhenpeng, Bai Lei
School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China.
College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
Org Lett. 2021 Apr 16;23(8):2890-2894. doi: 10.1021/acs.orglett.1c00535. Epub 2021 Mar 26.
A class of -symmetric chiral spirocyclic phase-transfer catalysts based on tetramethyl-1,1'-spirobiindane scaffold was synthesized from commercially available bisphenol A in 12 steps with 22-25% total yields, which features a more rigid and stable backbone and smaller dihedral angles and can be easily modified. These catalysts show high catalytic performance in the asymmetric alkylation of -butyl glycinate Schiff base at only 2 mol % catalyst loading, giving the target products with up to 92% yield and 98% ee.
一类基于四甲基-1,1'-螺双茚骨架的 - 对称手性螺环相转移催化剂由市售双酚A经12步合成，总收率为22 - 25%，其具有更刚性和稳定的主链以及更小的二面角，并且易于修饰。这些催化剂在 - 丁基甘氨酸 Schiff 碱的不对称烷基化反应中仅以2 mol%的催化剂负载量就表现出高催化性能，得到的目标产物收率高达92%，对映体过量值为98%。
