Broadband¹H homodecoupled NMR experiments: recent developments, methods and applications

Abstract

In recent years, a great interest in the development of new broadband 1H homonuclear decoupled techniques providing simplified JHH multiplet patterns has emerged again in the field of small molecule NMR. The resulting highly resolved 1H NMR spectra display resonances as collapsed singlets, therefore minimizing signal overlap and expediting spectral analysis. This review aims at presenting the most recent advances in pure shift NMR spectroscopy, with a particular emphasis to the Zangger-Sterk experiment. A detailed discussion about the most relevant practical aspects in terms of pulse sequence design, selectivity, sensitivity, spectral resolution and performance is provided. Finally, the implementation of the different reported strategies into traditional 1D and 2D NMR experiments is described while several practical applications are also reviewed.

Structure elucidation of uniformly 13C labeled small molecule natural products

“…Recently developed pure shift analogs of the HSQC experiment have served to further increase resolution and sensitivity. [10][11][12] In addition to 1 H and 13 C chemical shifts, HSQC spectra provide a wealth of structurally relevant information. In fact, there are successful examples of using just 1 H and multiplicityedited 1 H-13 C HSQC data for automated structure verification purposes.…”

Uniform Reduction of Scalar Coupling by Real‐Time Homonuclear J‐Downscaled NMR

“…[1][2][3][4][5] However, informationa bout scalar coupling, whichi so ften keyf or structural analysis,i sc ompletely lost in such homonuclear broadbandd ecoupleds pectra. However, compared to othern uclei, hydrogen hasalimited spectral rangeo fo nly~15 ppm.…”

“…[15] While ap rojectionp erpendicular to the diagonal yields af ully decoupled spectrum, any other projection would result in aJ -downscaled spectrum. [3,18,19] The acquisition is halted every~20 ms. During the FID interruption,t he homonuclear scalar coupling evolution is slice-selectivelyr efocused for ac ertain time and allowed to evolve again just before the start of Scalar coupling in protonN MR spectra provides important informationf or the structural analysis. [17] Here we present at echniquet ou niformly manipulate homonuclear scalar coupling constants in the direct acquisition dimension (i.e.…”

Structure elucidation of uniformly 13C labeled small molecule natural products

“…Recently developed pure shift analogs of the HSQC experiment have served to further increase resolution and sensitivity. [10–12] In addition to 1 H and 13 C chemical shifts, HSQC spectra provide a wealth of structurally relevant information. In fact, there are successful examples of using just 1 H and multiplicityedited 1 H– 13 C HSQC data for automated structure verification purposes.…”