Beyond inertness: silicone grease as an unintentional reagent

This review examines accidental and unanticipated reactivity involving silicone grease since 2016, when the last review on the same topic was published. Despite its perceived inertness arising from the robust siloxane backbone of polydimethylsiloxane formulations, numerous reports describe unexpected reactions with organometallic reagents, leading to siloxane bond cleavage and incorporation of –SiMe 2 O– fragments into organometallic species. For most reactions where silicone grease is involved, the mechanism is unclear, yet a strong acid or base in the reaction environment is typically the trigger of depolymerization of the silicone grease. • Despite its inertness, silicone grease is prone to unintended reactions. • Polysiloxane grease may degrade under the influence of strong acids or bases. • Reports of unexpected side reactions involving silicone grease with organometallic compounds since 2016. • The findings call for caution in using silicone grease in organometallic synthesis.