On the Stereochemical Course of Palladium-Catalyzed Cross-Coupling of Allylic Silanolate Salts with Aromatic Bromides
作者:Scott E. Denmark、Nathan S. Werner
DOI:10.1021/ja910804u
日期:2010.3.17
palladium-catalyzed cross-coupling reactions of an enantioenriched, alpha-substituted, allylic silanolate salt with aromatic bromides has been investigated. The allylic silanolate salt was prepared in high geometrical (Z/E, 94:6) and high enantiomeric (94:6 er) purity by a copper-catalyzed S(N)2' reaction of a resolved allylic carbamate. Eight different aromatic bromides underwent cross-coupling with excellent
已经研究了钯催化的对映体富集的、α 取代的烯丙基硅烷醇盐与芳族溴化物的交叉偶联反应的立体化学过程。通过铜催化的 S(N)2' 反应分解的烯丙基氨基甲酸酯,以高几何 (Z/E,94:6) 和高对映体 (94:6 er) 纯度制备烯丙基硅烷醇盐。八种不同的芳香族溴化物以优异的结构位点选择性和立体特异性进行交叉偶联。立体化学相关性确定金属转移事件通过 Syn S(E)' 机制进行,该机制解释为芳基钯亲电试剂通过包含离散 Si-O-Pd 键的关键中间体的分子内传递。