Reversed-Polarity Synthesis of Diaryl Ketones via Palladium-Catalyzed Cross-Coupling of Acylsilanes
作者:Jason R. Schmink、Shane W. Krska
DOI:10.1021/ja2064318
日期:2011.12.14
Acylsilanes serve as acyl anion equivalents in a palladium-catalyzed cross-coupling reaction with aryl bromides to give unsymmetrical diaryl ketones. Water plays a unique and crucial activating role in these reactions. High-throughput experimentation techniques provided successful reaction conditions initially involving phosphites as ligands. Ultimately, 1,3,5,7-tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane
酰基硅烷在钯催化的与芳基溴化物的交叉偶联反应中用作酰基阴离子等价物,得到不对称的二芳基酮。水在这些反应中起着独特而关键的活化作用。高通量实验技术提供了成功的反应条件,最初涉及亚磷酸酯作为配体。最终,1,3,5,7-四甲基-6-苯基-2,4,8-trioxa-6-phosphaadamantane 被确定为提供具有更高转化率的寿命更长的催化剂。将其与钯环预催化剂结合使用,可实现最佳反应速率和产率。介绍了这种新方法的范围和局限性以及初步的机械洞察力。