We report nickel-catalyzed cross-coupling of methoxyarenes with alkylmagnesium halides, in which a methoxy group is eliminated. A wide range of alkyl groups, including those bearing β-hydrogens, can be introduced directly at the ipso position of anisole derivatives. We demonstrate that the robustness of a methoxy group allows this alkylation protocol to be used to synthesize elaborate molecules by
我们报告了镍催化的甲氧基芳烃与烷基卤化镁的交叉偶联,其中甲氧基被消除。广泛的烷基,包括那些带有 β-氢的烷基,可以直接在苯甲醚衍生物的 ipso 位置引入。我们证明甲氧基的稳健性允许该烷基化方案通过将其与传统的交叉偶联反应或氧化转化相结合来合成复杂的分子。这种方法的成功取决于使用烷基碘化镁,而不是氯化物或溴化物,这突出了卤化物在使用格氏试剂进行催化反应中的重要性。
Lewis Acid Assisted Nickel‐Catalyzed Cross‐Coupling of Aryl Methyl Ethers by C−O Bond‐Cleaving Alkylation: Prevention of Undesired β‐Hydride Elimination
In the presence of trialkylaluminum reagents, diverse aryl methyl ethers can be transformed into valuable products by C−O bond‐cleaving alkylation, for the first time without the limiting β‐hydride elimination. This new nickel‐catalyzed dealkoxylative alkylation method enables powerful orthogonal synthetic strategies for the transformation of a variety of naturally occurring and easily accessible anisole
Nickel-Catalyzed C–O Bond-Cleaving Alkylation of Esters: Direct Replacement of the Ester Moiety by Functionalized Alkyl Chains
作者:Xiangqian Liu、Jiaqi Jia、Magnus Rueping
DOI:10.1021/acscatal.7b00941
日期:2017.7.7
Two efficient protocols for the nickel-catalyzed aryl–alkyl cross-coupling reactions using esters as coupling components have been established. The methods enable the selective oxidative addition of nickel to acyl C–O and aryl C–O bonds and allow the aryl–alkyl cross-coupling via decarbonylative bond cleavage or through cleavage of a C–O bond with high efficiency and good functional group compatibility