Premium
Deracemization of Quinolonecarboxamides by Dynamic Crystalline Salt Formation and Asymmetric Photoreaction by Using the Frozen Chirality
Author(s) -
Yagishita Fumitoshi,
Takagishi Naoya,
Ishikawa Hiroki,
Kasashima Yoshio,
Mino Takashi,
Sakamoto Masami
Publication year - 2014
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201403056
Subject(s) - chirality (physics) , enantiopure drug , chemistry , diastereomer , salt (chemistry) , axial chirality , yield (engineering) , crystallization , solvent , stereochemistry , organic chemistry , photochemistry , enantioselective synthesis , catalysis , chiral symmetry , thermodynamics , nambu–jona lasinio model , physics , quantum mechanics , quark
Abstract An asymmetric photoreaction by using chirality provided by dynamic chiral salt formation was demonstrated. Crystallization of racemic 2‐quinolone‐3‐carboxamide and 2‐quinolone‐4‐carboxamide with enantiopure L ‐dibenzoyltartaric acid led to deracemization and gave high diastereomeric excess values of the crystalline salts in almost quantitative yield. The axial chirality was retained for a long period of time after the salts were dissolved in cooled solvent. The frozen chirality derived from the chiral salts was effectively transferred to the products by using a typical [2+2] photocycloaddition reaction with alkenes.