A definitive NMR solution for a simple and accurate measurement of the magnitude and the sign of small heteronuclear coupling constants on protonated and non-protonated carbon atoms

Simply successful: A proton-selective HSQMBC-TOCSY experiment can be used to measure small proton-carbon ( ⁿJ _CH; n>1) coupling constants on both protonated and non-protonated carbon atoms (see spectrum). The method combines in a single pulse scheme all the benefits of the widely used HSQMBC and HSQC-TOCSY experiments. The magnitude and the sign of ⁿJ _CH can be determined simply with excellent accuracy.