Direct thioesterification of aldehydes with thiols catalyzed by readily accessible rare earth/lithium amide RE[N(SiMe3)2]3(μ-Cl)Li(THF)3 is developed, which enables the preparation of a range of thioesters (31 examples) under room temperature and solvent-free conditions, without using any additive or external oxidant. This method provides a straightforward and atom-efficient approach for the thioester synthesis.