College of Chemistry and Molecular Engineering, School of Pharmaceutical Sciences, Zhengzhou University , No. 100, Science Road, Zhengzhou, Henan 450000, P. R. China.
J Org Chem. 2018 Feb 2;83(3):1160-1166. doi: 10.1021/acs.joc.7b02599. Epub 2018 Jan 16.
A bimetallic cooperative catalysis model has been reported for the asymmetric Friedel-Crafts (F-C) alkylation of indoles with trifluoromethyl pyruvates using Trost's intramolecular dinuclear zinc complex as the catalyst. This dinuclear zinc catalyst was prepared in situ by reacting the chiral ligand (S,S)-L2b with 2 equiv of ZnEt. A series of trifluoromethyl alcohol and indole-containing biological compounds were formed in moderate to good yields (up to 95%) with good enantioselectivity (up to 88% enantiomeric excess (ee)) in the presence of 10 mol % catalyst under mild conditions. A synergistic transition state model was proposed to explain the origin of the asymmetric induction.
已报道了一种双金属协同催化模型，用于使用 Trost 的内双金属锌配合物作为催化剂，在手性配体 (S,S)-L2b 与 2 当量的 ZnEt 反应原位制备，对三氟甲基丙酮酸盐与吲哚的不对称 Friedel-Crafts（F-C）烷基化反应。在温和条件下，当催化剂用量为 10 mol%时，该双金属锌催化剂可在中等至良好的收率（高达 95%）下形成一系列含三氟甲基醇和吲哚的生物化合物，对映选择性（高达 88%对映过量（ee））。提出了协同过渡态模型来解释不对称诱导的起源。
