Yoshinaga Yukako, Yamamoto Takeshi, Suginome Michinori
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
ACS Macro Lett. 2017 Jul 18;6(7):705-710. doi: 10.1021/acsmacrolett.7b00352. Epub 2017 Jun 20.
Helical poly(quinoxaline-2,3-diyl)s copolymers consisting of a coordinating unit, which bears a varied achiral, substituted 2,2'-bipyridyl pendant, and a chiral unit bearing chiral side chains were synthesized and used as a ligand in copper-catalyzed asymmetric cyclopropanation of olefins with diazoacetates, giving up to 91:9 er with high chemical yield. The enantioselection relied on the helical structure of . A single afforded either of a pair of enantiomers with high enantioselectivity by switching its helical sense by changing the reaction solvent from pure toluene to a 3/1 mixture of toluene and 1,1,2-trichloroethane.
由带有不同非手性、取代的2,2'-联吡啶侧基的配位单元和带有手性侧链的手性单元组成的螺旋状聚（喹喔啉-2,3-二基）共聚物被合成出来，并用作铜催化的烯烃与重氮乙酸酯的不对称环丙烷化反应中的配体，以高达91:9的对映体过量（er）和高化学产率得到产物。对映体选择性依赖于……的螺旋结构。通过将反应溶剂从纯甲苯变为甲苯与1,1,2-三氯乙烷的3/1混合物来改变其螺旋方向，单一的……能以高对映体选择性提供一对对映体中的任何一种。
