Complexation with Barium(II) Allows the Inference of the Absolute Configuration of Primary Amines by NMR

1999 ◽  
Vol 121 (41) ◽  
pp. 9724-9725 ◽  
Author(s):  
Blanca López ◽  
Emilio Quiñoá ◽  
Ricardo Riguera
Keyword(s):  
Absolute Configuration ◽  
Primary Amines ◽  
The Absolute

The CFTA Method: A Reliable Procedure for the Determination of the Absolute Configuration of Chiral Primary Amines by1H NMR Spectroscopic Analysis

2006 ◽  
Vol 45 (28) ◽  
pp. 4617-4619 ◽  
Author(s):  
Yoshio Takeuchi ◽  
Masaru Segawa ◽  
Hidehito Fujisawa ◽  
Kenji Omata ◽  
Siegfried N. Lodwig ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Spectroscopic Analysis ◽  
Primary Amines ◽  
Reliable Procedure ◽  
The Absolute

NMR Determinations of the Absolute Configuration of α-Chiral Primary Amines

2010 ◽  
Vol 12 (12) ◽  
pp. 2856-2859 ◽  
Author(s):  
Hiroki Fukui ◽  
Yukiharu Fukushi
Keyword(s):  
Absolute Configuration ◽  
Primary Amines ◽  
The Absolute

Regioselectivity and stereoselectivity in the reaction of cis-1,2,2-Trimethylcyclopentane-1,3-dicarboxylic anhydride (cis-camphoric anhydride) with chiral primary amines

1981 ◽  
Vol 34 (3) ◽  
pp. 665 ◽  
Author(s):  
KH Bell
Keyword(s):  
Carbonyl Group ◽  
Absolute Configuration ◽  
Kinetic Resolution ◽  
Optically Active ◽  
Primary Amines ◽  
The Absolute

The reaction between primary amines and cis-1,2,2 trimethylcyclopentane-1,3-dicarboxylic anhydride (3) has been shown to be regioselective for the less hindered carbonyl group. Kinetic resolution was observed when racemic primary amines and the (1R,3S) anhydride (3) were used. Similar stereoselectivity was found in the alternative reaction between racemic (3) and optically active primary amines. In both cases, the absolute configuration of the more reactive enantiomeric amine or anhydride could be correlated with a model (7). The use of (3) is recommended for the prediction of the absolute configurations of racemic and optically active primary amines.

2-Cyano-2-indolylpropanoic acid as a chiral derivatizing agent for the absolute configuration assignment of secondary alcohols and primary amines by 1 H NMR and VCD

2017 ◽  
Vol 28 (6) ◽  
pp. 762-782 ◽  
Author(s):  
Claudia I. Bautista-Hernández ◽  
Nayely Trejo-Carbajal ◽  
Erick A. Zúñiga-Estrada ◽  
Alberto Aristeo-Dominguez ◽  
Myriam Meléndez-Rodríguez ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Primary Amines ◽  
Secondary Alcohols ◽  
H Nmr ◽  
Configuration Assignment ◽  
Derivatizing Agent ◽  
Chiral Derivatizing Agent ◽  
The Absolute

Assignment of the Absolute Configuration of Monofunctional Compounds by Single Derivatization

2015 ◽  
Author(s):  
Josi M. Seco ◽  
Emilio Quiqoa ◽  
Ricardo Riguera
Keyword(s):  
Absolute Configuration ◽  
Graphical Model ◽  
Chemical Shifts ◽  
Alternative Methods ◽  
Primary Amines ◽  
Secondary Alcohols ◽  
The Absolute ◽  
Lower Temperature

The procedures shown in Chapter 3 allow the determination of the absolute configuration of several classes of compounds (Chapter 1, Figure 1.18), but they require the preparation of two derivatives and the comparison of their NMR spectra. Alternative methods have been developed for secondary alcohols and α-chiral primary amines. These are particularly suited for those cases where the amount of the available sample is low, and they require the preparation of only a single derivative [41–43, 55–56, 165]. There are three different approaches to using only a single derivatization to perform the assignment of those substrates [13, 165]. The first two are based on a controlled conformational change that is produced either by modification of the probe temperature [41, 165] or by selective complexation [42, 55, 56, 165]. The third one is based on the differences observed between the chemical shifts of the free alcohol and those of the 9-AMA ester derivative [43, 165]. In general, these single-derivatization procedures are limited to 1H NMR. Because the shift differences observed in 13C NMR are quite small, they produce insignificant Δδ values, and therefore the signs are not sufficiently accurate to produce a safe assignment [72]. Explanations and examples of applications are presented in the remainder of this chapter. For the assignment of secondary alcohols, a simple approach based on the use of a single MPA ester has proven to work very well [41, 165]. It is based on the controlled shift of the conformational equilibrium between the two main conformers (sp/ap) that were described in Chapter 1 for the MPA esters of secondary alcohols [36, 37]. Thus, for the assignment, it is only necessary to prepare either the (R)- or the (S)-MPA ester and then to compare the chemical shifts of L1/L2 in the spectra taken at room temperature and at a lower temperature [41]. Figure 4.2 presents a summary of the procedure and the graphical model expressing the ΔδT1T2 correlation between the sign and the stereochemistry for the assignment of secondary alcohols derivatized as (R)- or as (S)-MPA esters.

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