Described herein are compounds including at least one -thio carbonyl or nitrile moiety capable of liberating an active molecule selected from an ,-unsaturated ketone, aldehyde or nitrile. Also described herein are methods of using said compounds in perfumery as well as perfuming compositions or perfumed articles including the compounds. The compounds are represented by formula (I) where: a) m represents an integer from 1 to 6; b) Pro represents a hydrogen atom or a group susceptible of generating an odoriferous ,-unsaturated ketone, aldehyde or nitrile and is represented by the formulae (II) or (II) in which the wavy line indicates the location of the bond between said Pro and the sulfur atom S; and at least one of the Pro groups is of the formula (II) or (II). ##STR00001##