Atropisomeric lactam chemistry: catalytic enantioselective synthesis, application to asymmetric enolate chemistry and synthesis of key intermediates for NET inhibitors

The self-disproportionation of enantiomers (SDE): a menace or an opportunity?

“…Indeed, Kitagawa has found MPLC to be a highly useful and routine methodology to effect practical enantiopurification of scalemates resulting from catalyzed asymmetric reactions, e.g. in addition to the aforementioned case, ref. 12, 13 b , 14 and 59 .…”

“…Other examples of drugs exhibiting SDE are the mebroqualone-type GABAergic drugs possessing axial chirality 13b , 14 , 60 (see Section 4.2 New directions and novel, unconventional enantiopurification methods), cephalotaxine, 90 precursors to norepinephrine transporter inhibitors, 12 chloromezanone 54 ( 19 ), and benzodiazepine camazepam 54 ( 20 ) in addition to many others. 91 It is worth noting that focused research on the SDE properties of marketed drugs has never been systematically undertaken and all reported examples are the results of accidental or anecdotal observations.…”

Influence of TiO2 on prebiotic thermal synthesis of the Gly-Gln polymer

“…In principle, the synthesis of peptides involves both the use of condensation agents as catalysts or other different conditions, such as high pressure and temperature (Fouche and Rohlfing 1976;Simoneit 2004) and melting processes (Fouche and Rohlfing 1976;Fox and Harada 1960;Rohlfing and MacAlhaney 1976). The aspect of the enantiomeric purity in these syntheses, and the possible role of self-disproportion under chromatographic or sublimation conditions have been detailed to define possible scenarios for prebiotic source of enantiomerically enriched amino acids and peptides (Soloshonok 2006;Takahashi et al 2010;Ueki et al 2010).…”

Optical Purifications via Self‐Disproportionation of Enantiomers by Achiral Chromatography: Case Study of a Series of α‐CF3‐containing Secondary Alcohols

“…While for most synthetic and reaction chemistry aspects it is not detrimental to report enantiomerically impure compounds, this practice represents one of the deficiencies of the current organic chemistry methodology. [21][22][23][24][25] In particular, the latter approach might be a method of very general application as it can be applied for crystalline as well as liquid compounds. Thus, currently available methods for enantiomeric purification are unacceptably limited to crystallization, diastereomeric derivatization and preparative chromatography on chiral stationary phases.…”

“…In this context, one of the promising areas is the self-disproportionation of enantiomers (SDE) [3][4][5][6] demonstrating that optical purification of enantiomerically enriched compounds via separation of racemate from the excess enantiomer †7 can be achieved under achiral conditions of any type of phase-transition [8][9][10][11][12][13][14][15][16][17][18][19][20] or achiral chromatography. [21][22][23][24][25] In particular, the latter approach might be a method of very general application as it can be applied for crystalline as well as liquid compounds. However, the SDE still awaits a comprehensive study to explore its practical potential for enantiomeric purifications.…”