Regio- and stereoselective synthesis of 1,3-hydroxyl amines via palladium-catalyzed carbonate-carbamate transformation with unique stereoselectivity: Synthesis of 3-amino-4-penten-1-ols

Article abstract of DOI:10.1021/jo00085a039

The transformation of cyclic carbonates 1 to cyclic carbamates 4 is achieved in the presence of aryl or sulfonyl isocyanate by the catalysis of Pd(0) in high yield and with high structural flexibility. The reaction shows unique stereoselectivity: 3,4-disubstituted carbonates 2, irrespective of the composition of their stereoisomers, provide trans-5 exclusively or predominantly over cis-5. Mixtures of cis- and trans-3,5-disubstituted carbonates 3 furnish either cis-6 or trans-6 in high selectivity depending on the reaction conditions (kinetic or thermodynamic control, respectively). ¹H NMR and X-ray structure analyses of 5 and 6 indicate that the stereochemical outcome is governed by an A^1,2-strain between N-sulfonyl and C₅-vinyl substituents.