弱配位辅助的Ru催化C—H环化反应合成新型3-芳基异香豆素类化合物

Ruthenium(Ⅱ)-catalyzed C-H Annulation via Weak Coordination: Synthesis of Novel 3-Arylisocoumarins

以2-氧硫叶立德芳乙酮类化合物为原料,通过弱配位辅助的Ru催化C—H活化过程简捷高效地构建了异香豆素类化合物,并推测了反应机理。以[RuCl2(p-cymene)]2为催化剂,HFIP为溶剂,AgNTf2为添加剂,KOAc为碱,以33%~91%收率合成了14个目标产物,其中3个化合物未见文献报道,其结构经1H NMR,13C NMR和HR-MS(ESI)表征。反应条件温和,反应位点选择性高,底物普适性好,耐受多种官能团。

The isocoumarin structure motifs plays an important role in the fields of organic synthesis and pharmaceutical research. Ruthenium(Ⅱ)-catalyzed homocoupling annulations of arylsulfoxonium ylides through weakly coordinating to direct access isocoumarin derivatives have been achieved. This procotol was performed with [RuCl2(p-cymene)]2 as the catalyst, HFIP as the solvent, AgNTf2 as the additive, and KOAc as the base to deliever fourteen annulated products up to yield of 91%. All the compounds were characterized by 1H NMR, 13C NMR and HR-MS(ESI). The method features mild reaction conditions, a high position selectivity, broad substrate scope and excellent functional group tolerance. Finally, a plausible mechanism for the reaction was proposed.