Cerium catalyst promoted C–S cross-coupling: synthesis of thioethers, dapsone and RN-18 precursors

In this work, we present a novel, efficient and green methodology for the synthesis of thioethers by the C–S cross-coupling reaction with the assistance of [Ce(L-Pro)₂]₂Ox as a heterogeneous catalyst in good to excellent yields. A scale-up of the protocol was explored using an unpublished methodology for the synthesis of a dapsone-precursor, which proved to be very effective over a short time. The catalyst [Ce(L-Pro)₂]₂Ox was recovered and it was shown to be effective for five more reaction cycles.