Electrophilic aromatic substitution using fluorinated isoxazolines at the C5 position via C-F bond cleavage

Electrophilic aromatic substitution at the C5 position of isoxazolines and construction of a new quaternary carbon center were achieved in this paper. This is the first report of carbon-carbon (C-C) bond formation onto isoxazoline without compromising the ring structure. Various aromatics including heteroaromatics gave the desired products in good yields, especially aromatics bearing electron-donating groups. The reaction proceeds via the SEAr reaction mechanism, in which carbocation intermediates generated from the fluorinated isoxazolines via C-F bond cleavage reacted with aromatics.