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Related Experiment Video

Updated: Jul 16, 2025

Hyperpolarized Xenon for NMR and MRI Applications

Hyperpolarized Xenon for NMR and MRI Applications

Published on: September 6, 2012

StereoPHIP: Stereoselective Parahydrogen-Induced Polarization.

Mai T Huynh¹, Emily Buchanan¹, Sara Chirayil¹

¹Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA.

Angewandte Chemie (International Ed. in English)

|September 15, 2023

Summary

This summary is machine-generated.

This study introduces stereoPHIP, a new method using parahydrogen and chiral catalysts to create hyperpolarized 13C chiral molecules like lactic acid. This technique offers high stereoselectivity for producing valuable chiral substrates.

Keywords:

Lactate NMR Spectroscopy Parahydrogen-Induced Polarization Pyruvate Stereoselectivity

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Area of Science:

Hyperpolarized MRI
Organic Chemistry
Catalysis

Background:

Chirality is crucial in biological systems, with enantiomers often exhibiting different metabolic pathways.
Parahydrogen-induced polarization (PHIP) is an advanced technique for generating 13C-hyperpolarized substrates.
Asymmetric hydrogenation is a key process for synthesizing chiral molecules.

Purpose of the Study:

To develop a novel method, stereoPHIP, for producing 13C-hyperpolarized chiral substrates with high stereoselectivity.
To demonstrate the application of stereoPHIP in synthesizing enantiomers of lactic acid.
To explore the use of chiral rhodium(I) catalysts in the stereoPHIP process.

Main Methods:

Addition of parahydrogen to a prochiral substrate in the presence of a chiral catalyst.
Utilizing chiral rhodium(I) catalysts ((R,R) and (S,S) enantiomers) for asymmetric hydrogenation.
Employing polarization transfer to 13C spins to generate hyperpolarized lactate ester derivatives.

Main Results:

Achieved over 20% 13C hyperpolarization for L- and D-lactate ester derivatives with excellent stereoselectivity.
Demonstrated successful synthesis of both D- and L-lactic acid enantiomers using stereoPHIP.
Observed distinct differences in hyperpolarized 1H signal decay between the (R,R) and (S,S) catalysts.

Conclusions:

StereoPHIP successfully expands the capabilities of conventional PHIP for producing 13C hyperpolarized chiral molecules.
The method provides a highly stereoselective route to valuable chiral substrates.
This technique holds promise for applications in various scientific fields requiring chiral molecules.