使用α-氧代羧酸作为酰基源,开发了一种简便,有效的N-取代吡唑啉酮的氧化CH-H酰化方法。Cu(OAc)2和K 2 S 2 O 8的组合可使反应在空气中顺利进行,并以中等到极好的收率提供各种各样的4-酰基吡唑啉酮产品。据信这种转变的机理是通过铜诱导的脱羧反应形成酰基铜物质而进行的。该方法为将酰基部分直接安装到生物活性吡唑啉酮衍生物中提供了方便且有用的途径,该途径可进一步用于许多应用中。
Copper-catalyzed direct acylation of the alkenyl C-H bond in 1,2-dihydro-3H-pyrazol-3-ones has been developed, affording a series of 4-acylpyrazolones in moderate to good yields. Notably, this protocol involves readily accessible substrates and reagents, which have good functional group tolerance leading to pyrazolone derivatives under mild reaction conditions.