Enantioconvergent Hydroboration of <i>E</i>/<i>Z</i>-Mixed Trisubstituted Alkenes
Yinwei Bao, Cheng‐Gong Zheng, Kangyu Xiong, Chenke Hu, Peng Lu, Yuwen Wang, Zhan Lu
Abstract
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.