CeO2-Nanorods-Catalyzed Protoboration of Alkenes and Alkynes with Bis(pinacolato)diboron

The protoboration of alkenes and alkynes with B(2)pin(2) (pin=OCMe2CMe2O) using a heterogeneous CeO2 nanorods catalyst has been developed to afford the corresponding alkyl and vinyl boronate esters in 41-99% yield under mild reaction conditions. A series of aromatic and aliphatic alkenes and alkynes with synthetically important functional groups were well tolerated. In both the systems, the catalyst could be reused for up to six runs without significant loss in activity. Stoichiometric reactions revealed that the protoboration may proceed through the in situ formed catalytically active boryl species.

Automated summary

A heterogeneous CeO2 nanorods catalyst is used for the protoboration of alkenes and alkynes to produce alkyl and vinyl boronate esters with yields of 41-99% under mild reaction conditions. Both aromatic and aliphatic alkenes and alkynes with important functional groups show good tolerance. The catalyst can be reused up to six runs without significant loss in activity. Stoichiometric reactions suggest that the protoboration proceeds via in situ formed catalytically active boryl species.