Absolute configuration assignment of oxindole derivatives by vibrational circular dichroism exciton coupling.

Abstract A convenient and reliable approach for the absolute configuration assignment of oxindole derivatives 2a – m by vibrational circular dichroism (VCD) measurements and evaluation of the VCD bisignated couplet resulting from the interaction of the C2 and C9 carbonyl groups is presented. The absolute configuration assignments were further tested by 1 H NMR measurements and by X-ray diffraction analysis.