Centre for Synthesis and Chemical Biology, School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
Angew Chem Int Ed Engl. 2016 Sep 5;55(37):11115-9. doi: 10.1002/anie.201604840. Epub 2016 Jul 15.
Readily available chiral diol scaffolds are useful as sources of chirality for asymmetric synthesis, however, few such scaffolds are readily available in enantiopure form. Reported herein is a cheap and modular synthesis of a novel family of chiral ferrocenyl diols in excellent yields with excellent enantio- and diastereoselectivity (>99 % ee and 99 % de). These diols possess not only planar and central chirality, but also axial chirality around the central iron atom. Characterization of these diols by X-ray crystallography revealed intra- and intermolecular hydrogen-bond networks depending on substitution at the carbinol positions. The potential of these diols as catalysts was subsequently demonstrated in an asymmetric hetero-Diels-Alder reaction which provided cycloadducts in up to 84 % yield with ee values ranging from -92 to +72 %.
易于获得的手性二醇骨架可用作不对称合成的手性源，然而，很少有这样的骨架以对映纯的形式容易获得。本文报道了一种新型手性二茂铁基二醇的廉价和模块化合成方法，该方法具有优异的对映选择性和非对映选择性（>99%ee 和 99%de），产率高。这些二醇不仅具有平面和中心手性，而且在中心铁原子周围还具有轴向手性。通过 X 射线晶体学对这些二醇进行的表征揭示了根据醇位取代情况存在分子内和分子间氢键网络。这些二醇作为催化剂的潜力随后在不对称杂 Diels-Alder 反应中得到了证明，该反应以高达 84%的收率和从-92 到+72%ee 值提供了环加成产物。
