Palladium-Catalyzed Synthesis of Aryl Ketones by Coupling of Aryl Bromides with an Acyl Anion Equivalent
作者:Akihiro Takemiya、John F. Hartwig
DOI:10.1021/ja064782t
日期:2006.11.1
Palladium-catalyzed couplings of aryl bromides with N-tert-butylhydrazones as acyl anion equivalents to form aryl ketones are reported. The coupling process occurs at the C-position of hydrazones to form N-tert-butyl azo compounds. Isomerization of these azo compounds to the corresponding hydrazones, followed by hydrolysis, gave the desired mixed alkyl aryl ketones. The selectivity of C- versus N-arylation
据报道,钯催化的芳基溴化物与作为酰基阴离子等价物的 N-叔丁基腙形成芳基酮的偶联。偶联过程发生在腙的 C 位以形成 N-叔丁基偶氮化合物。这些偶氮化合物异构化为相应的腙,然后水解,得到所需的混合烷基芳基酮。C-与N-芳基化的选择性受到氮上取代基的强烈影响。N-叔丁基腙发生碳芳基化,而N-芳基腙发生N-芳基化。含有伯和仲烷基以及芳基的腙的芳基化在水解后以良好的产率得到所需的酮。芳环上的官能团,如烷氧基、氰基、三氟甲基、碳烷氧基、氨基甲酰基和酮基,被容忍了。该反应可能通过从含有 eta1-二氮杂烯丙基配体的中间体中形成 CC 键的还原消除而发生。