Characteristic Conformation of Mosher’s Amide Elucidated Using the Cambridge Structural Database
AbstractConformations of the crystalline 3,3,3-trifluoro-2-methoxy-2-phenylpropanamide derivatives (MTPA amides) deposited in the Cambridge Structural Database (CSD) were examined statistically as Racid-enantiomers. The majority of dihedral angles (48/58, ca. 83%) of the amide carbonyl groups and the trifluoromethyl groups ranged from –30° to 0° with an average angle θ1 of −13°. The other conformational properties were also clarified: (1) one of the fluorine atoms was antiperiplanar (ap) to the amide carbonyl group, forming a staggered conformation; (2) the MTPA amides prepared from primary amines showed a Z form in amide moieties; (3) in the case of the MTPA amide prepared from a primary amine possessing secondary alkyl groups (i.e., Mosher-type MTPA amide), the dihedral angles between the methine groups and the carbonyl groups were syn and indicative of a moderate conformational flexibility; (4) the phenyl plane was inclined from the O–Cchiral bond of the methoxy moiety with an average dihedral angle θ2 of +21°; (5) the methyl group of the methoxy moiety was ap to the ipso-carbon atom of the phenyl group. View Full-Text
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Ichikawa, A.; Ono, H.; Mikata, Y. Characteristic Conformation of Mosher’s Amide Elucidated Using the Cambridge Structural Database. Molecules 2015, 20, 12880-12900.
Ichikawa A, Ono H, Mikata Y. Characteristic Conformation of Mosher’s Amide Elucidated Using the Cambridge Structural Database. Molecules. 2015; 20(7):12880-12900.Chicago/Turabian Style
Ichikawa, Akio; Ono, Hiroshi; Mikata, Yuji. 2015. "Characteristic Conformation of Mosher’s Amide Elucidated Using the Cambridge Structural Database." Molecules 20, no. 7: 12880-12900.