Asymmetric Ring-Closing Aminooxygenation of Alkenes en Route to 2-Amino-1,3-Diols with Vicinal Stereocenters

Article abstract of DOI:10.1021/acs.orglett.0c02452

A ring-closing aminooxygenation of alkenes with N-benzoyloxycarbamates occurs with very high diastereoselectivity (typically >20:1 d.r.) and very high enantioselectivity (up to 99percent ee). The reaction is catalyzed by a recently developed chiral-at-metal ruthenium complex at catalyst loadings of 0.5-1.0 mol percent. The reaction is proposed to proceed through a ruthenium nitrenoid intermediate that depending on the nature of the substrate undergoes either an aminooxygenation (1,2-disubstituted alkenes) or stops at the stage of the aziridination (trisubstituted alkenes), which can then be ring opened with benzoic acid. The resulting chiral cyclic carbamates can be hydrolyzed under basic conditions to provide versatile chiral 2-amino-1,3-diols with vicinal stereocenters.