Enantioconvergent Hydroboration of E / Z -Mixed Trisubstituted Alkenes.

The lack of mode for chirality recognition makes it particularly challenging to carry out asymmetric transformations on E / Z -mixed minimally functionalized trisubstituted alkenes. Here, we report a catalytic enantioconvergent hydroboration of minimally functionalized trisubstituted E / Z -mixed alkenes to construct chiral organoboronic esters with excellent enantioselectivity using chiral radical cobalt catalyst. This C(sp 3 )-H borylation protocol showed good functional group tolerance and products could be converted to valuable compounds via C-B derivatizations. The mechanistic studies, which included control experiments, nonlinear effect experiments, deuterated labeling experiments, and X-ray diffraction, demonstrated that the favorable compatibility between the thermodynamically unfavorable isomerization and hydroboration was the key factor in achieving convergent transformation.