Homonuclear decoupling in the ¹³C indirect dimension of HSQC experiments for ¹³C-enriched compounds

The two most compelling methods for broadband homonuclear decoupling currently available, Zangger–Sterk (ZS) and pure shift yielded by chirp excitation (PSYCHE), were successfully adapted and tested on the 13C isotope. When applied during the indirect carbon evolution in the HSQC experiment, they both entirely eliminated the extended carbon–carbon multiplet structures observed in this dimension of a non‐decoupled HSQC spectrum of 13C‐enriched cholesterol. The optimized selective pulse modulated using novel non‐equidistant scheme for multisite refocusing (ZS) and the small flip angle saltire chirps (PSYCHE) both proved to be robust and efficient in providing decoupled spectra with a sensitivity of about 25% that of the non‐decoupled HSQC spectra with improved quality compared to earlier results