Diphenylparabanic Acid as a Synthon for the Synthesis of α-Diketones and α-Ketocarboxylic Acids
作者:Nobuko Watanabe、Mitsutaka Hamano、Shota Todaka、Takahiro Asaeda、Hisako K. Ijuin、Masakatsu Matsumoto
DOI:10.1021/jo202304x
日期:2012.1.6
Diphenylparabanic acid was found to react with >2 equiv of organolithiums at −78 °C to effectively give the corresponding symmetrical α-diketones. However, upon treatment with 1 equiv of organolithium, the parabanic acid gave mainly 5-substituted 5-hydroxyimidazolidine-2,4-diones. On the other hand, Grignard reagents were less reactive toward the parabanic acid at low temperature, and selectively gave
reductive coupling reaction was established for the synthesis of diaryl 1,2-dicarbonyl compounds from arylmethyl ketones in good yields. The mechanisticstudy showed the reaction undergoes C(CO)–C(sp3) bond cleavage, with the reductive coupling reaction occurring through an electron transfer process. Notably, the reaction not only is simple to operate but also has mild reaction conditions and a wide