Determination of Heteronuclear Long-Range 1H–13C and 1H–15N Coupling Constants of Harman by Modified J-HMBC 2D NMR Techniques

Selective and double-selective J-HMBC 2D methods were developed and employed to determine the coupling constants of harman (1). The 1H–13C and 1H–15N long-range coupling constants could be accurately determined without interference from the 1H–1H J-modulation effect. We also applied selective J-HMBC 2D to 2-fluoropyridine (2) to confirm effectiveness.