Iron-Catalyzed Diborylation of Unactivated Aliphatic gem-Dihalogenoalkenes: Synthesis of 1,2-Bis(boryl)alkanes.

Herein, we report the first example of iron-catalyzed defluoroborylation of unactivated gem-difluoroalkenes, gem-dichloroalkenes, and gem-dibromoalkenes, providing the 1,2-bis(boryl)alkanes in moderate to good yield. This transformation has high regioselectivity, wide substrate scope, and excellent functional group compatibility. Preliminary mechanistic studies indicate that double β-F elimination is involved in the catalytic cycle, and the 1,1-diborylated alkenes might be intermediates in this iron-catalyzed 1,2-diborylation reaction.