Department of Chemistry, University of California , Berkeley, California 94720, United States.
J Am Chem Soc. 2018 Jan 31;140(4):1239-1242. doi: 10.1021/jacs.7b12824. Epub 2018 Jan 17.
We report stereodivergent allylic substitution reactions of allylic esters with prochiral enolates derived from azaaryl acetamides and acetates to form products from addition of the enolates at the most substituted carbon of an allyl moiety with two catalysts, a chiral metallacyclic iridium complex and a chiral bisphosphine-ligated copper(I) complex, which individually control the configuration of the electrophilic and nucleophilic carbon atoms, respectively. By simple permutations of enantiomers of the two catalysts, all four stereoisomers of products containing two stereogenic centers were synthesized individually with high diastereoselectivity and enantioselectivity. A variety of azaaryl acetamides and acetates bearing pyridyl, benzothiazolyl, benzoxazolyl, pyrazinyl, quinolinyl and isoquinolinyl moieties were all found to be suitable for this transformation.
我们报告了烯丙基酯与手性烯醇盐的立体发散性亲核取代反应，烯醇盐是由氮芳基乙酰胺和乙酸酯衍生而来，形成了产物，其中两个催化剂，手性金属环铱配合物和手性双膦配体铜（I）配合物，分别控制亲电和亲核碳原子的构型，各自控制烯丙基部分的最取代碳的加成。通过两种催化剂的对映异构体的简单置换，可以单独合成含有两个手性中心的产物的全部四个立体异构体，具有高的非对映选择性和对映选择性。发现各种含有吡啶基、苯并噻唑基、苯并恶唑基、吡嗪基、喹啉基和异喹啉基部分的氮芳基乙酰胺和乙酸酯都适合这种转化。
