Survey of NMR experiments for the determination of ~nJ(C,H) heteronuclear coupling constants in small moleucles

摘要

A survey of heteronuclear correlation experiments for the measurement of heteronuclear coupling constants is presented. The purpose of this survey is to evaluate several recent experiments for measuring ~nJ(C,H) (n = 2, 3) coplings in one comprehensive review. Ten experiments are presented and evaluated relative to tone another in tems of experimental usability, ease of data interpretation and number of usable correlations. The xperiments compared in this survey are the sensitivity-improved hetero-(#omega#_1)-half-filtered TOCSY (HETLOC), carbon-sorted HETLOC (HSQC-HECADE), coupled/decoupled HSQC-TOCY, GSQUBC, HSQMBC, G-BIRD_(R,X)-HSQMBC, J-resolved HMBC-2, J-IMPEACH-MBC and methods for extracting heteronuclear coupling constants from gradient-selected variants of the magnitude-mode and phase-sensitive HMBC. The plant alkaloid strychnine was used as a model compound for this study.