Phthalides as the
crucial core skeletons are found extensively
in natural products and biological active molecules. Herein we disclose
an asymmetric allylation of 3-hydroxyisobenzofuran-1(3H)-ones with boron allylation reagents to construct chiral phthalide
derivatives. The simple Bi(OAc)3/chiral phosphoric acid
catalytic system proves to be efficient in this method, delivering
the desired chiral 3-allylisobenzofuran-1(3H)-ones
in good yields (up to 99%) and high enantioselectivities (up to 99.5:0.5
e.r.) under mild conditions. The large-scale reaction and diverse
transformations of products to various scaffolds with potential biological
activities render it more attractive. Moreover, the mechanism was
preliminarily explored by control reactions, mass spectrometry, deuterium
experiment, and DFT calculations.