TY - JOUR
T1 - Selective heteronuclear NOE enhancements in benzoheterocycles. Effect of ring size on indirect three‐spin effects
AU - Redondo, Jordi
AU - Sánchez‐Ferrando, Francisco
AU - Valls, Montserrat
AU - Virgili, Albert
PY - 1988/1/1
Y1 - 1988/1/1
N2 - The 80 MHz 1H NMR and 20 MHz 13C NMR spectra of five 4‐methylcoumarins, six 4‐methyl‐2(1H)‐quinolones and nine 3‐methylbenzo[b]furans, including six new compounds, were fully assigned. Homonuclear 1H{1H} NOEs and selective heteronuclear 13C{1H} NOEs were measured after low‐power pre‐saturation of the methyl protons. Indirect, negative heteronuclear NOE enhancements were found in suitable three‐spin systems of the 13C1H{1H} type, and their magnitude was found to be dependent on ring size. The first examples of indirect, heteronuclear NOE enhancements on non‐protonated carbons are described. Copyright © 1988 John Wiley & Sons, Ltd.
AB - The 80 MHz 1H NMR and 20 MHz 13C NMR spectra of five 4‐methylcoumarins, six 4‐methyl‐2(1H)‐quinolones and nine 3‐methylbenzo[b]furans, including six new compounds, were fully assigned. Homonuclear 1H{1H} NOEs and selective heteronuclear 13C{1H} NOEs were measured after low‐power pre‐saturation of the methyl protons. Indirect, negative heteronuclear NOE enhancements were found in suitable three‐spin systems of the 13C1H{1H} type, and their magnitude was found to be dependent on ring size. The first examples of indirect, heteronuclear NOE enhancements on non‐protonated carbons are described. Copyright © 1988 John Wiley & Sons, Ltd.
KW - 13 1 1 C H{ H} three‐spin effects
KW - 2(1H)‐Quinolones
KW - Benzo[b]furans
KW - Coumarins
KW - Heteronuclear NOE
KW - Indirect Negative NOE
KW - Selective heteronuclear C{ H} NOE 13 1
U2 - 10.1002/mrc.1260260615
DO - 10.1002/mrc.1260260615
M3 - Article
SN - 0749-1581
VL - 26
SP - 511
EP - 517
JO - Magnetic Resonance in Chemistry
JF - Magnetic Resonance in Chemistry
IS - 6
ER -