Achieving High Levels of NMR‐Hyperpolarization in Aqueous Media With Minimal Catalyst Contamination Using SABRE

Abstract

Signal amplification by reversible exchange (SABRE) is shown to allow access to strongly enhanced 1 H NMR signals in a range of substrates in aqueous media. To achieve this outcome, phase-transfer catalysis is exploited, which leads to less than 1.5×10-6  mol dm-3 of the iridium catalyst in the aqueous phase. These observations reflect a compelling route to produce a saline-based hyperpolarized bolus in just a few seconds for subsequent in vivo MRI monitoring. The new process has been called catalyst separated hyperpolarization through signal amplification by reversible exchange or CASH-SABRE. We illustrate this method for the substrates pyrazine, 5-methylpyrimidine, 4,6-d2 -methyl nicotinate, 4,6-d2 -nicotinamide and pyridazine achieving 1 H signal gains of approximately 790-, 340-, 3000-, 260- and 380-fold per proton at 9.4 T at the time point at which phase separation is complete.

DOI: 10.1002/chem.201702716

Cite this paper

@inproceedings{Iali2017AchievingHL, title={Achieving High Levels of NMR‐Hyperpolarization in Aqueous Media With Minimal Catalyst Contamination Using SABRE}, author={Wissam Iali and Alexandra M Olaru and Gary G. R. Green and Simon B Duckett}, booktitle={Chemistry}, year={2017} }