Determination of the signs of long-range proton spin coupling constants by nuclear magnetic triple resonance

1964 ◽  
Vol 7 (1) ◽  
pp. 45-56 ◽  
Author(s):  
A.D. Cohen ◽  
R. Freeman ◽  
K.A. McLauchlan ◽  
D.H. Whiffen
Keyword(s):  
Long Range ◽  
Proton Spin ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Triple Resonance ◽  
Spin Coupling Constants ◽  
Nuclear Magnetic

scholarly journals Signs of proton–proton and proton–fluorine spin–spin coupling constants in 2-fluoro-3-methylpyridine. Sigma and pi contributions to coupling in a nitrogen heterocycle

1969 ◽  
Vol 47 (9) ◽  
pp. 1507-1514 ◽  
Author(s):  
T. Schaefer ◽  
S. S. Danyluk ◽  
C. L. Bell
Keyword(s):  
Nitrogen Atom ◽  
Long Range ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Nitrogen Heterocycle ◽  
Triple Resonance ◽  
Triple Resonance Experiments ◽  
Proton Proton ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

The signs of all proton–proton and proton–fluorine spin–spin coupling constants in 2-fluoro-3-methylpyridine have been determined by double and triple resonance experiments. The signs of the longrange coupling constants, JH,CH3 and JF,CH3 are the same as in fluorotoluene derivatives. Their magnitudes are consistent with the assumption that the nitrogen atom primarily polarizes the σ bonds in the molecule, leaving the π contribution to the long-range coupling relatively unaffected.

Stereochemical Determination of Acyclic Structures Based on Carbon−Proton Spin-Coupling Constants. A Method of Configuration Analysis for Natural Products

1999 ◽  
Vol 64 (3) ◽  
pp. 866-876 ◽  
Author(s):  
Nobuaki Matsumori ◽  
Daisuke Kaneno ◽  
Michio Murata ◽  
Hideshi Nakamura ◽  
Kazuo Tachibana
Keyword(s):  
Natural Products ◽  
Proton Spin ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Spin Coupling Constants

scholarly journals Long-range proton–carbon coupling constants for the determination of the stereochemical structure of organic compounds.

2021 ◽  
pp. 125-131
Author(s):  
Anwar, E. M. Noreljaleel
Keyword(s):  
Nmr Spectroscopy ◽  
Organic Compounds ◽  
Long Range ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Spectroscopy Method ◽  
Stereochemical Structure ◽  
New Methods ◽  
Spin Coupling Constants

A new methods for elucidating stereochemistry of organic compounds was developed on the basis of long-range proton–carbon coupling constants (2,3JC,H) and interpreting spin-coupling constants (3JH,H). Reaction of compound containing pyrin ring with nucleophile reagent was done to open the ring. HSQC-TOCSY experiments one of the new NMR spectroscopy method used to measure this values of spin-coupling constants and elucidating the stereochemistry of the product.

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