Methods for the enantioselective direct oxygenation of internal alkenes have provided chemists with versatile and powerful toolboxes for the synthesis of optically pure alcohols, one of the most privileged structural motifs. Regioselectivity, however, remains a formidable challenge in the functionalization of internal alkenes. Here we report a palladium-catalysed highly regio- and enantioselective remote 1,n-dioxygenation (n ≥ 4) of internal alkenes with engineered pyridine-oxazoline (Pyox) ligands. The reactions proceed efficiently and exhibit a broad substrate scope with excellent regio- and enantioselectivity, affording optically pure 1,n-diol acetates as the key synthons for important bioactive molecules. Experimental studies and density functional theory calculations provide evidence that the regioselectivity is governed by the reactivity disparity of two allylic C–H bonds, where the oxypalladation is reversible and the first palladium migration step proves to be the regioselectivity-determining step, enabled by the modified phenyl-substituted Pyox ligands.

内部烯烃的对映选择性直接氧化方法为化学家提供了多功能和强大的工具箱，用于合成光学纯醇，这是最特殊的结构基序之一。然而，区域选择性仍然是内部烯烃功能化的一个巨大挑战。在这里，我们报告了钯催化的高度区域选择性和对映选择性远程 1，n-双氧化（n≥4  ）内部烯烃与工程吡啶-恶唑啉 (Pyox) 配体。反应高效进行并表现出广泛的底物范围，具有出色的区域选择性和对映选择性，提供光学纯 1, n-二醇乙酸酯作为重要生物活性分子的关键合成子。实验研究和密度泛函理论计算提供的证据表明，区域选择性受两个烯丙基 C-H 键的反应性差异控制，其中氧钯化是可逆的，第一个钯迁移步骤被证明是区域选择性决定步骤，通过修改苯基取代的 Pyox 配体。