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Determination of the Absolute Configuration of ( S )‐ N ‐(1‐Aryl‐allyl)‐3,5‐dinitrobenzamides and Their Elution Order on Brush‐Type Chiral Stationary Phases
Author(s) -
Knežević Anamarija,
Novak Jurica,
Pescitelli Gennaro,
Vinković Vladimir
Publication year - 2018
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.201800346
Subject(s) - chemistry , steric effects , aryl , acylation , candida antarctica , absolute configuration , stereocenter , elution , atropisomer , kinetic resolution , organic chemistry , lipase , circular dichroism , stereochemistry , amine gas treating , chromatography , enzyme , catalysis , enantioselective synthesis , alkyl
A series of ten enantiomerically pure ( S )‐ N ‐(1‐aryl‐allyl)‐3,5‐dinitrobenzamides ( S ‐DNBs) was prepared using enzymatic resolution and chiral chromatography. Enzymatic resolution of corresponding 1‐aryl‐allylamines using Candida antarctica lipase B (CaLB) was efficient for amines with no steric hindrance near the stereogenic center and S ‐DNB amides were prepared by acylation of the obtained S ‐amine. When steric effects interrupted enzymatic resolution, racemic DNB amides were resolved using a brush‐type chiral column ( CSP‐A ) developed in our laboratory. Previously reported behavior of CaLB in kinetic resolution of amines was considered a starting point for the determination of absolute configuration (AC). The AC of prepared S ‐DNB amides was anticipated using the elution order of prepared DNB amides on CSP‐A and commercial Whelk‐O1 columns and comparison with DNB amides obtained after acylation of ( S )‐amines. The comparison between experimental electronic circular dichroism (ECD) spectra with those obtained by conformational analysis and ECD calculations of representative compounds allowed us to verify the AC of prepared DNB amides.