Asymmetric Synthesis of 1,3-Diamines. II: Diastereoselective Reduction of Atropisomeric N–tert-Butanesulfinylketimines

Martjuga, M.; Belyakov, S.; Liepinsh, E.; Suna, E. J. Org. Chem. 2011, 76, 2635–2647.

DOI: 10.1021/jo1025767

Abstract

Chiral, nonracemic o-aminobenzylamines were prepared in a highly diastereoselective reduction of atropisomeric Ntert-butanesulfinylketimines. The ortho-substituent ensures the distinct reactivity of atropisomers 4df. The free energy of activation for atropisomerization of sulfinylimines 4df in THF-d8 was determined by NMR methods to range from 70.8 to 97.9 kJ/mol.