C–C Activation by Retro-Aldol Reaction of Two β-Hydroxy Carbonyl Compounds: Synergy with Pd-Catalyzed Cross-Coupling To Access Mono-α-arylated Ketones and Esters
作者:Song-Lin Zhang、Ze-Long Yu
DOI:10.1021/acs.joc.5b02098
日期:2016.1.4
retro-aldol reaction of two β-hydroxy compounds in synergy with Pd-catalyzed cross-coupling of aryl halides is reported herein, which produces selectively mono-α-arylated ketones and esters in good yields. This reaction is compatible with a broad range of aryl iodides, bromides, chlorides, and triflates and can tolerate an array of functional groups on the aromatic ring. Ready scale-up of this reaction to gram
本文报道了两种β-羟基化合物的逆醛醇缩合反应与芳族卤化物的Pd催化的交叉偶联协同作用,其以良好的产率选择性地产生单α-芳基化的酮和酯。该反应与广泛范围的芳基碘化物,溴化物,氯化物和三氟甲磺酸酯相容,并且可以耐受芳族环上的一系列官能团。在不明显降低反应收率的情况下,可将该反应准备好按比例放大至克级。此外,已经实现了生物活性异香豆素和吲哚衍生物的简明合成,以极大地证明该逆醛醇缩合反应的合成价值。最后,在实验观察和DFT计算结果的基础上讨论了反应机理。一个调节的六元环过渡结构已被定位用于关键的逆醛醇C–C裂解,这构成了整个催化循环的速率决定步骤。逆向醇醛缩合反应激活C–C的概念也可能在其他基本反应中得到应用。