Alkenylboronates represent a cornerstone functional group in modern organic synthesis owing to their versatile reactivity in Suzuki-Miyaura cross-coupling reactions and other key transformations. However, catalytic asymmetric methods for producing stereodefined tetrasubstituted axially chiral alkenylboronates remain underdeveloped. Here, we report a copper-catalyzed atroposelective protoboration of allenes, providing a facile strategy to access tetrasubstituted axially chiral Z-alkenylboronates with excellent regio- and atroposelectivities. The enantiomerically enriched axially chiral alkenylboronates could be further transformed into diverse stereodefined tetrasubstituted axially chiral olefins via the cross-coupling reaction of the C-B bond. This methodology also provides a new avenue to construct C-C or C-N axially chiral alkene-phosphine frameworks.
Li et al. (Wed,) studied this question.