Theoretical calculations on rhodium(III)-Cp* catalyzed asymmetric transfer hydrogenation of acetophenone using monosulfonamide ligands derived from (1R,2R)-diaminocyclohexane

Abstract

Chiral secondary alcohols are valuable synthetic intermediates in the pharmaceutical industry in making complex biologically active molecules. Noyori’s ATH of aromatic ketones using Ru(II)-monotosylated diamine complexes are catalyst is one the useful methods to induce high yields and enantioselectivities in the formation of the secondary alcohol. Using Ru(II) as catalyst, the calculated energy difference between the Re and Si transition state were found to be 2.1kcal/mol. We found Rh(III)Cp*-monotosylated diamine complexes gave better results in aqueous conditions compared to the Ru(II) complexes in the ATH of aromatic ketones. Here we show a similar calculation for the transition state involving Rh(III), which gives the energy difference between the Re and Si to be 3.9kcal/mol.