AbstractParahydrogen‐induced polarization (PHIP) followed by polarization transfer to 13C is a rapidly developing technique for the generation of 13C‐hyperpolarized substrates. Chirality plays an essential role in living systems and differential metabolism of enantiomeric pairs of metabolic substrates is well documented. Inspired by asymmetric hydrogenation, here we report stereoPHIP, which involves the addition of parahydrogen to a prochiral substrate with a chiral catalyst followed by polarization transfer to 13C spins. We demonstrate that parahydrogen could be rapidly added to the prochiral precursor to both enantiomers of lactic acid (D and L), with both the (R,R) and (S,S) enantiomers of a chiral rhodium(I) catalyst to afford highly 13C‐hyperpolarized (over 20 %) L‐ and D‐lactate ester derivatives, respectively, with excellent stereoselectivity. We also show that the hyperpolarized 1H signal decays obtained with the (R,R) and (S,S) catalysts were markedly different. StereoPHIP expands the scope of conventional PHIP to the production of 13C hyperpolarized chiral substrates with high stereoselectivity.
摘要 对氢诱导极化(PHIP)后极化转移到 13C 是一种快速发展的生成 13C 超极化底物的技术。手性在生命系统中起着至关重要的作用,对映体对代谢底物的差异代谢也是有据可查的。受不对称氢化的启发,我们在此报告了立体氢化对映体(stereoPHIP),它涉及在手性催化剂的作用下将对氢添加到亲手性底物中,然后极化转移到 13C 自旋。我们证明,在手性
铑(I)催化剂的(R,R)和(S,S)对映体的作用下,可将对氢快速加入到
乳酸的两种对映体(D 和 L)的原手性前体中,分别得到高度 13C 超极化(超过 20%)的 L
乳酸酯和 D
乳酸酯衍
生物,并具有极佳的立体选择性。我们还发现,(R,R) 和 (S,S) 催化剂得到的超极化 1H 信号衰减明显不同。StereoPHIP 将传统 PHIP 的应用范围扩展到生产具有高立体选择性的 13C 超极化手性底物。