Enantiomerization of an atropisomeric drug

Nonbiaryl and Heterobiaryl Atropisomers: Molecular Templates with Promise for Atropselective Chemical Transformations

“…Detailed experimental studies and concepts on these topics have already been discussed in various reports. 125,126,128,131,132 Table 1 provides the physical parameters of the racemization for some of the commonly occurring atropisomeric scaffolds. It should be noted that some of the Table 1 are not atropisomeric, as they do not have high energy barriers to separation.…”

Serendipitous discovery of a pH-dependant atropisomer bond rotation: Toward a write-protectable chiral molecular switch?☆

“…The chromatographic separation of slowly interconverting atropisomers is a popular subject within the field of chiral chromatography, with molecules from diverse structural classes having been studied using a variety of chromatographic techniques [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. We herein report the serendipitous discovery of an unusual interconverting atropisomer system, 1, where a strong influence of pH on carboxamide bond rotation is observed.…”

NMR Studies of Crowded Diels–Alder Adducts of 3,6‐Dibromophencyclone withN‐(2,6‐Dialkylphenyl)maleimides. Hindered Rotations and Magnetic Anisotropy. Ab Initio Calculations for Optimized Structures of the Precursor Maleimides and Their Adducts with Phencyclone and 3,6‐Dibromophencyclone

“…Rotations about bonds to aromatic rings, especially C-aryl and N-aryl rotations, have been particularly significant for numerous drug systems. Some examples include the C-aryl rotation in the benzodiazepine, ketazolam [9] and the N-aryl rotations in the potential antipsoriatic, Sch40120, [10] the muscle relaxant, afloqualone, [11] famprofazone (an analog of amphetamine) [12] and antipyrine. [13,14] N-Aryl rotations have also been important in the strictly controlled (Schedule I of the Controlled Substances Act) sedative-hypnotics, methaqualone, [15] and mecloqualone.…”