Experimental and Theoretical Studies on Cobalt-Catalyzed Regioselective Hydrosilylation of Tetrafluorinated Cyclohexa-1,3-dienes

Cyclohexa-1,3-dienes bearing a tetrafluoroethylene group underwent highly regioselective hydrosilylation in the presence of 1-10 mol % Co-2(CO)(8) in 1,2-dichloroethane under mild conditions (reflux, 3 h), which led to an abundant yield of homoallylsilanes. Mechanistic studies proved that the reaction proceeds as per the modified Chalk-Harrod mechanism; via DFT calculation, the reason for homoallylsilanes being exclusively obtained was demonstrated. The formal synthesis of a tetrafluorinated negative-type liquid crystal demonstrated the synthetic utility of such hydrosilylation.

Automated summary

In this study, highly regioselective hydrosilylation of cyclohexa-1,3-dienes bearing a tetrafluoroethylene group was achieved under mild conditions using 1-10 mol % Co-2(CO)(8) as the catalyst. Mechanistic studies and DFT calculations demonstrated that the reaction proceeds via the modified Chalk-Harrod mechanism, leading to the exclusive formation of homoallylsilanes. The successful synthesis of a tetrafluorinated negative-type liquid crystal showcased the synthetic utility of this hydrosilylation reaction.