Visible-light-driven Oxidation of 1,3-Dicarbonyl Compounds via Catalytic Disproportionation of TEMPO by Photoredox Catalysis
作者:Takashi Koike、Yusuke Yasu、Munetaka Akita
DOI:10.1246/cl.2012.999
日期:2012.9.5
Visible light irradiation of a mixture of 1,3-dicarbonyls and 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) in the presence of photoredox catalysts, [Ru(bpy)3]2+ and [Ir(ppy)2(dtbbpy)]+ (bpy: 2,2′-bipyridine, ppy: 2-phenylpyridine, dtbbpy: 4,4′-di-tert-butyl-2,2′-bipyridine), afforded two types of oxidized products, i.e., α-oxyaminated products from acyclic 1,3-dicarbonyls and oxidatively dimerized products from cyclic 1,3-dicarbonyls. The Ir catalyst turned out to be more active than the Ru catalyst. This is a new photocatalytic oxidation of 1,3-dicarbonyls based on a single-electron-transfer process mediated by excited photoredox catalysts.
可见光照射下,1,3-二羰基化合物与2,2,6,6-四甲基哌啶-1-氧基(TEMPO)在光氧化还原催化剂[Ru(bpy)3]2+和[Ir(ppy)2(dtbbpy)]+(bpy:2,2'-联吡啶,ppy:2-苯基吡啶,dtbbpy:4,4'-二叔丁基-2,2'-联吡啶)存在下反应,生成两种氧化产物,即非环状1,3-二羰基化合物的α-氧氨基化产物和环状1,3-二羰基化合物的氧化偶联产物。结果表明,铱催化剂的活性高于钌催化剂。这是一种基于激发态光氧化还原催化剂介导的单电子转移过程的新型1,3-二羰基化合物光催化氧化反应。