Enantiomeric impurities in chiral catalysts, auxiliaries and synthons used in enantioselective synthesis

Enantioselective synthesis of (S)-phenylephrine by whole cells of recombinant Escherichia coli expressing the amino alcohol dehydrogenase gene from Rhodococcus erythropolis BCRC 10909

“…The absolute configurations of (R)-PE and (S)-PE were therefore determined by HPLC method using a CYCLOBOND I 2000 AC column. The CYCLOBOND I 2000 AC column, which is based upon the acetylated beta cyclodextrin form, has the potential to resolve many aromatic alcohols or amines that are chiral at the alpha or beta carbon [27][28][29]. According to the chromatogram of chiral-HPLC, the retention times for HPMAE, (R)-PE, and (S)-PE were 13.5, 14.8, and 18.6 min, respectively (Fig.…”

Supramolecular systems‐based extraction‐separation techniques coupled to mass spectrometry

“…CD-based GC has been applied to many fields of enantiomeric analysis [70,[76][77][78][79] including essential oils, flavors, and fragrants [70,80], ingredients in alcoholic beverages [81,82], clinical chemistry [83], terpenoids [84], pheromones [85], enzymatic reactions [86], organochlorine pesticides [87][88][89][90], atmospheric alkyl nitrates [91], and volatile pharmaceutical compounds [92,93].…”

Enantiomeric impurities in chiral catalysts, auxiliaries, and synthons used in enantioselective syntheses. Part 4

“…Also it has been shown that the batch to batch enantiomeric purity of the same compound from the same supplier can differ considerably. 4 Thus having a facile method available to evaluate chiral reagents also is useful.…”

“…2,4,5 The majority of chiral reagents were determined to have moderate to low levels (<1%) of enantiomeric impurities, while some had unexpectedly high levels (>10%). The general level of enantiomeric impurities reported in 2006 was lower than that reported in 1998-1999.…”