Regioselective Catalytic Asymmetric C-Alkylation of Isoxazolinones by a Base-Free Palladacycle-Catalyzed Direct 1,4-Addition
作者:Tina Hellmuth、Wolfgang Frey、René Peters
DOI:10.1002/anie.201410933
日期:2015.2.23
asymmetric alkylations of isoxazolinones forming all‐C‐substituted quaternary stereocenters. The present studies were driven by the question of how to control the regioselectivity in the competition of different nucleophilic positions. The investigation of a direct 1,4‐addition uncovered that a sterically demanding palladacycle catalyst directs the reactivity in the absence of a base nearly exclusively to
异恶唑啉酮构成一类用于开发新型候选药物的杂环。环状肟酯基序也可用于合成,因为它含有功能性手柄,以前已被用来提供对各种有价值的化合物类别的访问,而这些化合物是其他方法无法轻易获得的。然而,众所周知,针对异恶唑啉酮的不对称方法是稀缺的。在本文中,我们报告了异恶唑啉酮的第一个催化不对称烷基化反应,形成了全C取代的季立体中心。本研究受到在不同亲核位置竞争中如何控制区域选择性的问题的驱动。直接调查1,