An Efficient and General Method for the Reformatsky-Type Reaction of Chlorodifluoromethyl Ketones with Carbonyl Compounds Giving α,α-Difluoro-β-hydroxy Ketones
作者:Manabu Kuroboshi、Takashi Ishihara
DOI:10.1246/bcsj.63.428
日期:1990.2
Specific activation of zinc metal with the metal salt is essential to achieve high efficiency of the reaction, depending upon the structures of the chlorodifluoromethyl ketones and the carbonyl compounds employed. In-situ formed intermediates in these reactions were successfully detected by 19F NMR spectroscopy, which suggests that their structure is not an α-metallo ketone but an oxygen-metallated
氯二氟甲基酮 CF2ClCOR,其中 R 是烷基、芳基和 1-炔基,在酸洗锌粉和氯化铜 (I) 或银存在下,与多种醛或酮发生 Reformatsky 型羟醛反应醋酸盐得到相应的 α,α-二氟-β-羟基酮,收率很好。根据氯二氟甲基酮和所用羰基化合物的结构,用金属盐对锌金属进行特定活化对于实现反应的高效率是必不可少的。这些反应中原位形成的中间体通过 19F NMR 光谱成功检测到,这表明它们的结构不是 α-金属酮,而是具有锌 (II) 金属作为抗衡阳离子的氧金属化物质。