Silica-promoted facile synthesis of thioesters and thioethers: a highly efficient, reusable and environmentally safe solid support

An efficient, mild and rapid procedure for the acylation and alkylation of aromatic and aliphatic thiols mediated on a silica gel surface at room temperature is described. The protocol allows the protection of thiols under neutral heterogeneous conditions without requiring any bases or Lewis acids, and the silica gel used as the promoter can be recycled for several runs without any loss of activity.