for the preparation of 3-substituted isocoumarins via palladium-catalyzed nucleophilic addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective nucleophilic addition and C–H functionalization procedure.
Modular synthesis of 3-substituted isocoumarins <i>via</i> silver-catalyzed aerobic oxidation/<i>6-endo</i> heterocyclization of <i>ortho</i>-alkynylbenzaldehydes
作者:Hao Wu、Yi-Chun Wang、Andrey Shatskiy、Qiu-Yan Li、Jian-Quan Liu、Markus D. Kärkäs、Xiang-Shan Wang
DOI:10.1039/d1ob01065d
日期:——
A method involving silver-catalyzed aerobic oxidation/6-endo heterocyclization of ortho-alkynylbenzaldehydes to yield 3-substituted isocoumarins is described. The developed protocol allows convenient access to a range of synthetically useful 3-substituted isocoumarins and related fused heterocyclolactones in good to high yields, using silver tetrafluoroborate as the catalyst, and atmospheric oxygen