Taming Tethered Nitreniums for Alkene Functionalization Reactions

We present the first examples of amino-trifluoroacetoxylations of alkenes using N-alkoxy carbamate tethers. Hypervalent iodine oxidants mediate this transformation, providing a "green" alternative to existing intramolecular amino-hydroxylation protocols which use toxic metals such as osmium. In all cases examined, the reaction is regioselective and stereospecific, with the geometry of the starting alkene controlling the diastereomeric outcome. By analogy to prior art and from our own observations, we posit that a transient nitrenium species serves as a key intermediate.