Details

Autor(en) / Beteiligte

• Alvarez-Cisneros, Celina
• Muñoz, Marcelo A
• Suárez-Castillo, Oscar R
• Pérez-Hernández, Nury
• Cerda-García-Rojas, Carlos M
• Morales-Ríos, Martha S
• Joseph-Nathan, Pedro

Titel

Stereospecific (5) JHortho,OMe couplings in methoxyindoles, methoxycoumarins, and methoxyflavones

Ist Teil von

• Magnetic resonance in chemistry, 2014-09, Vol.52 (9), p.491-499

Ort / Verlag

England

Erscheinungsjahr

2014

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Long-range coupling constants (5) JHortho,OMe were measured in series of methoxyindoles, methoxycoumarins, and methoxyflavones by the modified J doubling in the frequency domain method. The COSY and NOESY spectra revealed the coupling of the -OMe group with a specific proton at the ortho position and its preferred conformation. Homonuclear (1) H-(1) H couplings were confirmed by irradiation of the -OMe signal. Density functional theory calculations of (5) JHortho,OMe using the modified aug-cc-pVTZ basis set evidenced that the Fermi contact term shows good agreement with the experimental J values. Accurate chemical shift and coupling constant values followed after iterative quantum mechanical spectral analysis using the PERCH software.