BrCCl3 and CBr4 was develop, enabling Kharasch-type addition/nucleophilic substitution cascade to selectively produce α-gem-dihalovinyl ketones and chromen-2-ones with moderate to good yields. Use of monoalkynes without additional nucleophilic sites furnished α-gem-dihalovinyl ketonesthrough a Kharasch-type addition and intermolecular allylic substitution cascade whereas the latter transformation of 2-ethynylphenols