The addition of the aromatic phosphate reagent as the HAT catalyst is essential for product formation (entry e). CeF4 as a cerium salt, proved most successful for generating product 4 (entry a), however using CeO2 as a heterogenous lanthanoid catalyst gave 33% of the C-S coupled product (entry f). The yield could be further increased by replacing Cs2CO3 with Na2CO3 as the (entry h).