Visible Light-Induced Photoredox Construction of Trifluoromethylated Quaternary Carbon Centers from Trifluoromethylated Tertiary Bromides

A mild,
operationally simple, visible light-induced photoredox
method for constructing novel trifluoromethylated quaternary carbon
centers from trifluoromethylated tertiary bromides has been developed.
Using this method, a wide range of alkenes were successfully bifunctionalized
to γ-butyrolactams. As for electron-rich alkenes, reactions
catalyzed by Ir­(dF­(CF3)­ppy)2(dtbbpy)­(PF6) were kinetic processes with high yields and short times.
For styrenes, reactions catalyzed by Ir­(ppy)2(dtbbpy)­(PF6) were thermodynamic processes with moderate yields and prolonged
reaction times. For aliphatic alkenes, the reactions were neither
thermodynamic nor kinetic and fac-Ir­(ppy)3 was used as catalyst. Thus, reactions were not as efficient as electron-rich
alkenes. The atom-transfer radical addition reactions of trifluoromethylated
tertiary bromides with alkynes were also achieved. The configuration
of products we separated was E type only. Some of
the products exhibited bactericidal activity.