Silicon Polonovski Reaction. Formation and Synthetic Application of α-Siloxy Amines

Article abstract of DOI:10.1246/bcsj.60.3291

A new and versatile synthetic intermediate, α-siloxy amine was prepared in situ by the base-promoted rearrangement of a siloxyammonium salt obtained by treatment of a tertiary amine N-oxide with trialkylsilyl trifluoromethanesulfonate.The best combination of the base and silylating reagent was found to be methyllithium and t-butyldimethylsilyl trifluoromethanesulfonate.The reactions of α-siloxy amines with acyl halides and haloformates gave the corresponding amides and carbamates in moderate to good yields, respectively.Treatment of α-siloxy amines with acetic acid resulted in a direct dealkylation to free secondary amines.Fluoride induced alkylation of α-siloxy amines using alkyl halides as electrophiles leading to tertiary amines was also examined and demonstrated to be a new transalkylation method of amines.