Co2(CO)8 as an efficient catalyst for the synthesis of functionalized polymethylhydrosiloxane oils and unconventional cross-linked materials

Abstract

We report here the use of Co₂(CO)₈ as a cheap and structurally simple alternative to precious metals for the functionalization of polymethylhydrosiloxane (PMHS) with terminal alkenes. This catalytic system at 0.1 mol% loading was found capable of hydrosilylating PMHS with one or two different alkenes in up to >99% efficiency under mild conditions. More importantly, we investigated the synthesis of cross-linked PMHS materials and found that both traditional dienes and unconventional tethers (such as esters and 5-hexen-2-one) led to fast and effective cross-linking of PMHS via hydrosilylation of CC and CO bonds, and further formation of Si–O–Si bridges between the PMHS chains. Additionally, we demonstrate here the potential of using renewable resources such as oleic acid derivatives as suitable cross-linkers to prepare bio-sourced cross-linked silicone materials.