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 C
O 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.