Deoxygenative Haloboration and Enantioselective Chloroboration of Carbonyls

Deoxygenative difunctionalization of carbonyls affords a straightforward and effective route to construct geminal dual functionalized motifs. However, the research in this field is very challenging due to the strong bond dissociation energies of the C-O double bond or the subsequently formed C-O bond. Herein, we report a highly efficient deoxygenative haloboration of aldehydes to generate secondary alpha-haloboronates. Meanwhile, the difficult-to-obtain tertiary alpha-haloboronates can be also readily prepared via the same strategy with ketones. Furthermore, enantioselective chloroboration of carbonyls was successfully achieved to give chiral secondary or tertiary alpha-chloroboronates, the important intermediates to access enantioenrich multisubstituted stereocenters. These versatile products can be surprisingly attained through this simple and mild process with remarkable substrate scope expansion and functional group tolerance. Additionally, these reactions can proceed well on large scales, giving more practical values in the application.

Automated summary

In this study, a highly efficient deoxygenative haloboration of carbonyls was reported to generate secondary or tertiary alpha-haloboronates. Furthermore, enantioselective chloroboration of carbonyls was successfully achieved to give chiral secondary or tertiary alpha-chloroboronates, providing important intermediates for the synthesis of enantioenriched multisubstituted stereocenters.