Morpholine Derivative Usable for Introduction of a Trifluoromethyl Group

4-[2,2,2-Trifluoro-1-[(trimethylsilyl)oxy]ethyl]morpholine (1) is a morpholine-derived hemiaminal ether and a useful trifluroromethlyating agent, first reported by Langlois et al. and Amii et al. independently. 1 acts as a nucleophilic CF₃ source and anion equivalent. In the presence of catalytic CsF, the CF₃ group of 1 nucleophilically can add to a variety of aromatic ketones and aldehydes with subsequent silylation of the carbonyl oxygen. Additionally, 1 can react with aryl iodides to add CF₃ in the presence of if excess CsF and a Cu-catalyst to afford CF₃-aryl species in high yield.