Intermolecular Synthesis Of ?-Tertiary Amine:Photoredox Hydroamination Of Trisubsituted Styrenes Via Visible-light Photoredox Catalysis

?-Tertiary amines,a functionality featured an amino group connected to a quaternary carbon centers,-have attracted the attention of synthetic chemists because they are more resistant to degradation than amines bearing an ?-hydrogen,and widely found in natural products and active pharmaceuticals.Visible light has been widely used in organic synthesis due to its advantages of low cost,easy access and environmental friendliness.The application of visible light in the synthesis of ?-quaternary amine is consistent with the concept of green chemistry.It is dyes rather than complex metal ligands that were used as photocatalysts,which is more economical and better avoid the metal residue.An efficient and green hydroamination with visible light and dyes as photocatalysts is reported.Under visible light,Safranin O was used to catalyze the addition of sulfamates with three substituted olefins containing aryl groups to obtain?-quaternary amines.2,2,2-Trifluoroethyl sulfamate was found to be the optimal nitrogen source because of its high yields,atom economy and easy deprotection.Safranin O which was used as photocatalyst is very good because it can be used directly from cheap commercial sources.The selectivity of this kind of reactions was very excellent:the products we obtained were quaternary amines,and no benzyl substitution products were detected.The deprotection of amine products can be carried out with high yield with convenient procedure.