Cobalt‐Catalyzed Enantioselective Negishi Cross‐Coupling of Racemic α‐Bromo Esters with Arylzincs
作者:Feipeng Liu、Jiangchun Zhong、Yun Zhou、Zidong Gao、Patrick J. Walsh、Xueyang Wang、Sijie Ma、Shicong Hou、Shangzhong Liu、Minan Wang、Min Wang、Qinghua Bian
DOI:10.1002/chem.201705463
日期:2018.2.9
enantioselective Negishi cross‐coupling reaction, and the first arylation of α‐halo esters with arylzinc halides, are disclosed. Employing a cobalt‐bisoxazoline catalyst, various α‐arylalkanoic esters were synthesized in excellent enantioselectivities and yields (up to 97 % ee and 98 % yield). A diverse range of functional groups, including ether, halide, thioether, silyl, amine, ester, acetal, amide, olefin
公开了第一个钴催化的对映选择性Negishi交叉偶联反应,以及α-卤代酯与芳基卤化锌的第一个芳基化反应。使用钴-二恶唑啉钴催化剂,可以以优异的对映选择性和高收率(高达97%ee和98%收率)合成各种α-芳基链烷酸酯 。该方法可耐受各种官能团,包括醚,卤化物,硫醚,甲硅烷基,胺,酯,乙缩醛,酰胺,烯烃和杂芳族化合物。该方法适用于克级反应,可合成高纯度的(R)-花草苷。自由基时钟实验支持自由基的中介作用。