PhotocatalyticAmine-Promoted Selective Hydrochlorinationand sp³ C–O Acylation of Alkyne-Tethered MethylEthers with Aldehydes

We present a photoredox and alkylamine-assisted approach for the selective hydrochlorination and acylation of sp³ C–O bonds in alkynyl methyl ethers using aldehydes. This method leverages a cascade of radical processesincluding chlorine radical addition, hydrogen atom transfer, <i>in situ</i> imine radical addition, and spin-center shiftto enable selective hydrochlorination of alkynes and the spontaneous cleavage of sp³ C–O bonds. The transformation accommodates a broad range of internal alkyne-tethered ethers and aldehydes, providing an efficient and streamlined pathway to chloro-alkenyl ketones. Utilizing only a photocatalyst, chloride, and propylamine under light irradiation, this strategy offers a practical and complementary alternative to previous sp³ C–O cleavage protocols.