RESUMEN
Structural analyses using Raman optical activity (ROA) spectroscopy conventionally rely on vibrational signals in the fingerprint region ranging from 100 to 1800 cm-1. Use of deuterium labelling to observe ROA signals in the C-D stretching region provides additional information about a local structure of large molecular systems. So far, the potential of C-D stretching ROA signals for structural analysis has rarely been explored. In the present work, we synthesized model deuterated glucose monosaccharides and studied their ROA properties by employing molecular dynamics and density functional theory to interpret the spectra. A good agreement between the simulated and experimental spectra is achieved when the proper conformer ratios are considered. This shows the usefulness of ROA spectroscopy assisted by deuterium labelling for stereochemical and conformational analysis.
RESUMEN
The colorless solution of furan-2-yl bis(indolyl)methane (BIM) is newly revealed to work as a palladium (Pd2+) ion-selective chromogenic agent by turning orange. 5-(N-Methyl-N-phenyl-aminomethyl)-furan-2-yl BIM could be synthesized from 5-chloromethylfurfural as a biorenewable feedstock via one-pot and double functionalization, and a mixture of its solution and Pd2+ ions showed the highest absorbance at 465 nm in UV-Vis analysis. On the other hand, other metal ions (Cu2+, Cr2+, Cr3+, Fe2+, Fe3+, Ni2+, Zn2+, In2+, Pt2+, or Ce3+) exhibited no response.
RESUMEN
The pharmacokinetics of pharmaceutical drugs can be improved by replacing C-H bonds with the more stable C-D bonds at the α-position to heteroatoms, which is a typical metabolic site for cytochrome P450 enzymes. However, the application of deuterated synthons is limited. Herein, we established a novel concept for preparing deuterated reagents for the successful synthesis of complex drug skeletons with deuterium atoms at the α-position to heteroatoms. (dn -Alkyl)diphenylsulfonium salts prepared from the corresponding nondeuterated forms using inexpensive and abundant D2 O as the deuterium source with a base, were used as electrophilic alkylating reagents. Additionally, these deuterated sulfonium salts were efficiently transformed into dn -alkyl halides and a dn -alkyl azide as coupling reagents and a dn -alkyl amine as a nucleophile. Furthermore, liver microsomal metabolism studies revealed deuterium kinetic isotope effects (KIE) in 7-(d2 -ethoxy)flavone. The present concept for the synthesis of deuterated reagents and the first demonstration of a KIE in a d2 -ethoxy group will contribute to drug discovery research based on deuterium chemistry.