Construction of α-Halogenated Boronic Esters via Visible Light-Induced C-H Bromination
Feng-Chen Gao, Ming Li, Heng-Yu Gu, Xin-Yi Chen, Shuang Xu, Yi Wei and Kai Hong*
*School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China,
Email: khong
chem.ecnu.edu.cn
F.-C. Gao, M. Li, H.-Y. Gu, X.-Y. Chen, S. Xu, Y. Wei, K. Hong, J. Org. Chem., 2023, 88, 14246-14254.
DOI: 10.1021/acs.joc.3c01915
see article for more reactions
Abstract
α-Halogenated boronic esters are versatile building blocks. A convenient visible light-induced C-H bromination reaction of readily available benzyl boronic esters provides α-brominated boronates in high yields under mild conditions and with good functional group tolerance. The analogous chlorides and iodides can be accessed via Finkelstein reaction.
see article for more examples
Note
Benzyl α-bromo boronates are generally labile on silica gel, so we only purified the hindered products. The less sterically demanding products were collected in an analytically pure form after a simple Celite filtration.
Kai Hong, July 17, 2024
P.-F. Ning, Y. Wei, X.-Y. Chen, Y.-F. Yang, F.-C. Gao, K. Hong, Angew. Chem. Int. Ed., 2023, 62, e202315232.
Key Words
NBS, benzyl bromides, benzyl boronates, α-haloboronates, photochemistry
ID: J42-Y2023
