Investigation into the chiral recognition mechanism of N-arylthiazolin-2(thi)one atropisomers on Chiralcel OJ by factorial design and lipophilicity approaches

Enantioselective correlation between retention factor and lipophilicity index in chiral separation on cellulose and amylose tris(3,5-dimethylphenylcarbamate) CSPs in reversed mode: A case study

“…12 The lipophilicity indexes (log kw) were available from previous studies. 12 The chosen method involved the determination of retention factor k of the compounds using an octadecyl-modified silica column (freed of silanol groups to prevent retention by other mechanisms) and a mobile phase consisting of different concentrations of methanol in water. The lipophilicity index, log kw, is obtained by extrapolation from the linear regression of the plot log k versus the percentage by volume of methanol to 100% water (polycratic method).…”

“…Furthermore, if the ln k of an enantiomer deviates from these lipophilic correlation lines, standing above or under the line, there are additional attractive or repulsive interactions, respectively. 12,13 Atropisomers 1-14 are chosen as model compounds since they possess two very different regions (e.g., heterocycle and phenyl, amide thioamide) in terms of polarity, hydrogen bonding, and stacking abilities. These two regions are situated in two well-defined perpendicular planes.…”

“…For these derivatives, lipophilicity, expressed as the lipophilicity index log kw, has been determined experimentally. 12 Furthermore, the relationship between the sign of rotation and absolute configuration is known. 14 The general structure of the compounds under study is shown in Figure 1, and specific numbering is reported in each Table. We now report the separation of atropisomers 1-14 on cellulose and amylose tris(3,5-dimethylphenylcarbamate) coated on silica (CHIRALCEL OD-R and CHIRALPAK AD-RH) in reversed elution mode (H 2 O/CH 3 CN (60:40)).…”

Synthesis and chiral separation of atropisomers of 4,5‐Di methyl ∆4 N‐phenyl N‐aryl imidazoline‐2‐thione derivatives

“…Further, the authors investigated the effect of substituents in the atropisomeric separation of N-arylthiazolinethione derivatives 18,19 and the mechanism of chiral recognition of these compounds was explored. 20 Moreover, Pirkle et al synthesized 40 atropisomers, generally described as oxothiazolinones, thiazolinones, and their sulfur derivatives, besides, the enantiomers of these compounds have been separated by high-performance liquid chromatography (HPLC) on synthetic chiral stationary phase known as the WEHLK-O1. 21 Recently, Roussel et al reported complete experimental and theoretical studies relating to the synthesis, evaluation of the barriers to rotation and resolution of atropisomeric enantiomers by chromatography on chiral supports of a series of original atropisomeric N-aryliminothiazolines.…”

Atropisomerism in a 10-Membered Ring with Multiple Chirality Axes: (3Z,9Z)-1,2,5,8-Dithiadiazecine-6,7(5H,8H)-dione Series

“…5,6 The UV trace showed a very clean crude reaction medium with two large peaks corresponding to the unreacted thiazolinethione 1 and the targeted thiazolinone 2 which were known in the laboratory. 2 In addition, two very minor extra peaks (ca 2% each) which were respectively eluted before and after the two main heterocycles attracted our attention (see SI). The CD (254 nm) detector trace was as expected silent for the two main compounds 1 and 2 but quite intriguingly two intense CD signals of opposite sign and similar intensity were associated to the two very minor peaks hardly detected in UV.…”