scholarly journals An ingenious method for the determination of the relative and absolute configurations of compounds containing aryl-glycerol fragments by 1H NMR spectroscopy

RSC Advances ◽  
2021 ◽  
Vol 11 (14) ◽  
pp. 8107-8116
Author(s):  
Xu Zhang ◽  
Kai-Zhou Lu ◽  
Hai-Wei Yan ◽  
Zi-Ming Feng ◽  
Ya-Nan Yang ◽  
...  

A concise method was established to determine the relative and absolute configurations of aryl-glycerols that depend on the chemical shift differences (Δδ) of the diastereotopic methylene protons (H-3) by 1H NMR spectroscopy.

1977 ◽  
Vol 32 (5) ◽  
pp. 589-593 ◽  
Author(s):  
Reiner Luckenbach ◽  
Hans-H. Bechtolsheimer

The preparation and separation into diastereomers of tbutyl-phenyl-phosphinic acid (—)-menthyl ester (1a) is reported. The diastereomeric purity as well as the absolute configuration at phosphorus of 1 a can be deduced from the detailed analysis of the 1H NMR spectra of samples of 1a differing in their diastereomer ratios.


2011 ◽  
Vol 6 (5) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Tatyana N. Makarieva ◽  
Larisa K. Shubina ◽  
Alla G. Guzii ◽  
Natalya V. Ivanchina ◽  
Vladimir A. Denisenko ◽  
...  

A study has been made of the 1H NMR spectra of peracetylated β-glucopyranosides and α-arabinopyranosides obtained by reaction of D- and L-glucoses, and L- and D-arabinoses with either ( R)- or ( S)-2-octanols. The obtained and literature data show that 1H NMR spectra may be used to determine the absolute configuration of the aglycone moieties of some alicyclic glycosides without the need to synthesize derivatives with chiral reagents, as long as the absolute configuration of their monosaccharide moiety is known or vice versa. Spectra of marine steroid glycosides and their acetates containing glycosylated side chains as alicyclic fragments were also examined. It was shown that analysis of 1H NMR spectra for the determination of the absolute configuration is more applicable in the cases when glycosides have the same substitution in the D-ring of the aglycone moiety.


1995 ◽  
Vol 73 (5) ◽  
pp. 635-642 ◽  
Author(s):  
David J. Law ◽  
Glen Bigam ◽  
Ronald G. Cavell

Treatment of [M(cod)Cl]2 (M = Rh, Ir) with iminophosphoranophosphine ligands of the type Ph2PQP(Ph2)=NSiMe3 (Q = CH2, CH2CH2, 1,2-C6H4) afforded the new metallacycles [Formula: see text] through elimination of Me3SiCl, ultimately "anchoring" the ligand to the metal through a metal–nitrogen σ bond. The phosphine functionality completes the chelate. Cationic complexes of the type [M(cod)L2]+PF6− (M = Rh or Ir; L2 = Ph2PQPPh2NR where Q = CH2, CH(CH3), 1,2-C6H4, and R = p-C6F4CN, C6H2F(NO2)2, and C6H3(NO2)2 or L = Ph2PN=C(H)Ph) were readily prepared by treating [M(cod)Cl]2 with L2 and KPF6. The detection and chemical shift determination of the insensitive 103Rh nucleus was easily accomplished via 31P detected indirect two-dimensional 31P, 103Rh{1H} NMR spectroscopy. The 103Rh, 1H, and 31P NMR data are discussed. Keywords: rhodium, iridium, phosphoranimine, iminophosphine, Rh NMR.


2020 ◽  
Vol 12 (28) ◽  
pp. 3626-3636
Author(s):  
Keshav Kumar ◽  
Ralf Schweiggert ◽  
Claus-Dieter Patz

In the current work, a novel procedure for correcting the peak drifts of 1H-NMR was introduced that involved mapping NMR spectra on a common chemical shift axis followed by interval-wisely applying the correlation optimized warping (COW) algorithm.


1985 ◽  
Vol 50 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milena Masojídková ◽  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Ivan Rosenberg ◽  
Antonín Holý

Conformational properties of ribonucleoside 5'-O-phosphonylmethyl derivatives have been determined by 1H NMR spectroscopy and compared with those of natural nucleosides and 5'-nucleotides.


Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 405 ◽  
Author(s):  
Brett H. Pogostin ◽  
Anders Malmendal ◽  
Casey H. Londergan ◽  
Karin S. Åkerfeldt

Determining the pKa of key functional groups is critical to understanding the pH-dependent behavior of biological proteins and peptide-based biomaterials. Traditionally, 1H NMR spectroscopy has been used to determine the pKa of amino acids; however, for larger molecules and aggregating systems, this method can be practically impossible. Previous studies concluded that the C-D stretches in Raman are a useful alternative for determining the pKa of histidine residues. In this study, we report on the Raman application of the C2-D probe on histidine’s imidazole side chain to determining the pKa of histidine in a short peptide sequence. The pKa of the tripeptide was found via difference Raman spectroscopy to be 6.82, and this value was independently confirmed via 1H NMR spectroscopy on the same peptide. The C2-D probe was also compared to other Raman reporters of the protonation state of histidine and was determined to be more sensitive and reliable than other protonation-dependent signals. The C2-D Raman probe expands the tool box available to chemists interested in directly interrogating the pKa’s of histidine-containing peptide and protein systems.


2018 ◽  
Vol 66 (44) ◽  
pp. 11873-11879 ◽  
Author(s):  
René Bachmann ◽  
Sven Klockmann ◽  
Johanna Haerdter ◽  
Markus Fischer ◽  
Thomas Hackl

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