Abstract
α-Boryl carbenes, which are hybrid structures combining elements of carbenes and boryl
groups, represent promising intermediates for constructing organoboron compounds.
However, these carbenes are challenging to synthesize and exhibit limited structural
diversity. Moreover, their applications in asymmetric transformations remain largely
unexplored. In this study, we utilized boryl cyclopropenes as precursors to rapidly
synthesize α-Bpin metal carbenes, a novel category of intermediates critical for the
synthesis of chiral organoboron molecules. Facilitated by a copper complex modified
by a chiral bisoxazoline ligand, these α-boryl carbenes participate in a range of
highly enantioselective transfer reactions, including B–H and Si–H insertions, as
well as cyclopropanation and cyclopropanation/Cope rearrangement processes. This methodology
provides access to previously inaccessible, yet highly useful, chiral organoborons,
thereby significantly advancing both carbene and organoboron chemistry.
1 Introduction
2 Previous Discovery and Our Design
3 Copper Catalyzed Enantioselective α-Boryl Carbene Transfer Reactions
4 Mechanistic Studies
5 Conclusions
Key words
α-boryl carbenes - asymmetric catalysis - cyclopropenes - carbene transfer reactions
- chiral organoborons
