In the presence of trimethylsilyl trifluoromethanesulfonate and trialkylamine base, thioesters are readily converted to silyl ketene acetals in situ and undergo Mukaiyama–Mannich addition to N-phenylimines in one pot. The silyl triflates appears to play two roles, activating both the thioester and the imine. This process also works well when thioesters are replaced with amides, esters, or ketones. Products are isolated as desilylated anilines without the necessity of a deprotection step. Yields range from 65-99%.
Copyright © 2015, European Journal of Organic Chemistry.
C. Wade Downey, Jared A. Ingersoll,* Hadleigh M. Glist,* Carolyn M. Dombrowski,* Adam T. Barnett.* One-pot silyl ketene acetal-formation-Mukaiyama–Mannich additions to imines mediated by trimethylsilyl trifluoromethanesulfonate. European Journal of Organic Chemistry 2015, 7287-7291.