By: Amit Pal, Fathima Niloofar, Basudev Sahoo
We report the first hydrothiocarbonylation of (un)activated alkynes using bench-stable 1,4-DHP thioester surrogates under photochemical conditions, enabling a general route to ( E )-α,β-unsaturated thioesters with excellent regio- and stereoselectivity. A Pd/photoredox catalytic system facilitates DHP thioester activation and site-selective hydrocarbonylation while controlling photoisomerization and side reactions. Moreover, a combination of benzil and boron Lewis acid pairs promotes E -to- Z photoisomerization, accessing ( Z )-α,β-unsaturated thioester.
