A cobalt-catalyzed, chemodivergent deoxygenative polyborylation strategy for silyl enol ethers has been developed, enabling selective synthesis of 1,1,1-triborylalkanes, 1,1,3-triborylalkanes, 1,1-diborylalkenes, and 1,1-diborylalkanes. Specifically, deoxygenative borylation with B2pin2 affords 1,1,1-triborylalkanes, 1,1,3-triborylalkanes, and 1,1-diborylalkenes, while the use of HBpin favors 1,1-diborylalkane formation. This protocol offers mild reaction conditions, a broad substrate scope, and high functional group tolerance. The utility and practicality of this method were demonstrated through gram-scale reactions and various product transformations. Mechanistic investigations revealed that all processes are initiated via the cobalt-catalyzed dehydrogenative and deoxygenative borylation of silyl enol ethers.
Dong et al. (2025) studied this question.