Synthesis of α-Heterosubstituted Ketones Through Sulfur Mediated Difunctionalization of Internal Alkynes

Synthesis of α-heterosubstituted ketones was achieved through sulfur mediated difunctionalization of internal alkynes in one-pot. The reaction design involves: phenyl substituted internal alkyne attacking the triflic anhydride activated diphenyl sulfoxide to give a sulfonium vinyl triflate intermediate, hydrolysis to give the α-sulfonium ketone, and then substitution with various nucleophiles. This method provides a unified route to access α-amino ketones, α-acyloxy ketones, α-thio ketones, α-halo ketones, α-hydroxy ketones, and related heterocyclic structures, in a rapid fashion.