Biaryl and Aryl Ketone Synthesis via Pd-Catalyzed Decarboxylative Coupling of Carboxylate Salts with Aryl Triflates
作者:Lukasâ
J. Goossen、Christophe Linder、Nuria RodrÃguez、Paulâ
P. Lange
DOI:10.1002/chem.200900892
日期:2009.9.21
the first time allows the decarboxylative cross‐coupling of aryl and acyl carboxylates with aryl triflates. In contrast to aryl halides, these electrophiles give rise to non‐coordinating anions as byproducts, which do not interfere with the decarboxylation step that leads to the generation of the carbon nucleophilic cross‐coupling partner. As a result, the scope of carboxylate substrates usable in this
已开发出一种双金属催化剂体系,该体系首次允许芳基和酰基羧酸盐与芳基三氟甲磺酸酯进行脱羧交叉偶联。与芳基卤化物相反,这些亲电试剂会产生非配位阴离子副产物,这些副产物不会干扰脱羧步骤,而脱羧步骤会导致亲核碳交联伙伴的产生。结果,可用于此转化的羧酸酯底物的范围从邻位取代或其他活化的衍生物扩展到广泛的邻位,间位和对位取代的芳族羧酸盐。优化了两种替代方案,一种方案涉及在存在铜的情况下加热基板I / 1,10-菲咯啉(10–15 mol%)和PdI 2 /膦(2–3 mol%)在NMP中作用1–24 h,另一项涉及Cu I / 1,10–菲咯啉(6–15 mol) %)和NMP中的PdBr 2 / Tol-BINAP(2 mol%)使用微波加热5-10分钟。尽管大多数产品都可以通过标准加热来获得,但发现微波辐射特别有益于将未活化的羧酸酯与官能化的芳基三氟甲磺酸酯转化。通过48个示例演示了该转换的综合效