Regioselective Base-Free Intermolecular Aminohydroxylations of Hindered and Functionalized Alkenes

Regioselective base-free intermolecular aminohydroxylations of functionalized trisubstituted and 1,1-disubstituted alkenes employing benzoyloxycarbamate <b>3a</b> and catalytic OsO<sub>4</sub> are described. In all cases, the more substituted alcohol isomer is favored. Sluggish reactions could be promoted by gentle heating, the use of amine ligands, or increased catalyst loadings. A competitive rearrangement was observed with a secondary allylic alcohol substrate. The adducts serve as useful precursors to dehydroamino acids.