Diastereoselective Synthesis of Boryl-Substituted Vinylcyclopropanes via Deborylative Cyclization of Geminal Diboron Compounds.

Herein we report a diastereoselective synthesis of boryl-substituted vinylcyclopropanes, a class of highly valuable synthetic building blocks, via deborylative cyclization of geminal diboron compounds. The method exhibits broad functional group tolerance and accommodates diverse alkyl and aryl α-substituents. The diastereoselectivity is primarily governed by the α-substituent (alkyl vs aryl), while olefin geometry in the side chain has a secondary influence.

Construction of α-Halogenated Boronic Esters via Visible Light-Induced C-H Bromination.

α-Halogenated boronic esters are versatile building blocks that can be diversified into a wide variety of polyfunctionalized molecules. However, their synthetic potential has been hampered by limited preparation methods. Herein, we report a visible light-induced C-H bromination reaction of readily available benzyl boronic esters.