Kikuchi Jun, Aramaki Hiromu, Okamoto Hiroshi, Terada Masahiro
Department of Chemistry , Graduate School of Science , Tohoku University , Aoba-ku , Sendai 980-8578 , Japan . Email:
Chem Sci. 2018 Nov 19;10(5):1426-1433. doi: 10.1039/c8sc03587c. eCollection 2019 Feb 7.
An FBINOL-derived chiral phosphoric acid was shown to be an effective catalyst for an enantioselective carbonyl-ene reaction of 1,1-disubstituted olefins with ethyl glyoxylate as the common enophile. The perfluoro-binaphthyl skeleton is beneficial not only for adopting high catalytic activity but also for creating an effective chiral environment for enantioselective transformations. Indeed, the reaction afforded enantio-enriched homoallylic alcohols in high yields with high enantioselectivities. Theoretical studies identified that the multi-point C-H···O hydrogen bonds and the π interactions between the substrates and the 6-methoxy-2-naphthyl substituents at the 3,3'-positions of the FBINOL skeleton play a crucial role in determining the stereochemical outcomes. The significance of the perfluoro-binaphthyl skeleton in achieving the high enantioselectivity was also evaluated through a structural analysis of the catalysts.
一种源自联萘酚的手性磷酸被证明是一种有效的催化剂，可用于1,1 - 二取代烯烃与乙醛酸乙酯作为常见亲烯体的对映选择性羰基烯反应。全氟联萘骨架不仅有利于获得高催化活性，还能为对映选择性转化创造有效的手性环境。实际上，该反应以高对映选择性和高产率得到了对映体富集的高烯丙醇。理论研究表明，FBINOL骨架3,3'-位上的底物与6 - 甲氧基 - 2 - 萘基取代基之间的多点C - H···O氢键和π相互作用在决定立体化学结果方面起着关键作用。还通过对催化剂的结构分析评估了全氟联萘骨架在实现高对映选择性方面的重要性。
