Determination of Enantiomeric Composition of Substituted Tetrahydroisoquinolines Based on Derivatization with Menthyl Chloroformate

Abstract

A method for the analysis of the optical purity of a series of chiral substituted tetrahydroisoquinolines (THIQs) was developed. The method is based on pre-column derivatization of the analytes with the derivatization reagent (-)-(1R)-menthyl chloroformate. The derivatization reaction selectively gives diastereomeric carbamates that are resolvable on an achiral non-polar GC column. The developed technique covers variously substituted THIQs, which differ significantly in volatility, steric and electronic properties. In all cases, the resolution factors (R) exceeded the value of 1.5. The method represents a robust way of analysis of mixtures of THIQs, which are often present in various matrixes such as body fluids, tissues and reaction mixtures.

Role of the sulfonamide moiety of Ru(II) half-sandwich complexes in the asymmetric transfer hydrogenation of 3,4-dihydroisoquinolines

“…Least squares linear regression was used for the calculation of reaction rate r from the initial linear region. The ee values were measured by GC using a previously reported method [31] The complexes were studied by monitoring the reaction kinetics of asymmetric transfer hydrogenation of imines 1-methyl-3,4-dihydroisoquinoline (3) and 6,7-dimethoxy-1-methyl-3,4-dihydroisoquinoline (4). The reactions were performed in round-bottom flasks as we described previously in our parametric study [16].…”

“…The residue was dissolved in 1 mL of acetonitrile and analyzed via GC. After the addition of triethylamine (20 lL) and (-)-(R)-menthyl chloroformate (10 lL), the enantiomeric excess (ee) was determined by GC using a previously reported method [31].…”

Asymmetric Transfer Hydrogenation of 1‐Aryl‐3,4‐Dihydroisoquinolines Using a Cp*Ir(TsDPEN) Complex

“…orthophosphoric acid - Table S2, entries 5-15), the 85 % aq. Therefore, orthophosphoric acid was investigated further, including the anhydrous phosphoric acid (APA) [11] prepared by mixing the 85 % H 3 PO 4 with stoichiometric amounts of phosphorus pentoxide (Table S2, entries [16][17][18][19][20][21][22][23][24][25][26][27][28]. Therefore, orthophosphoric acid was investigated further, including the anhydrous phosphoric acid (APA) [11] prepared by mixing the 85 % H 3 PO 4 with stoichiometric amounts of phosphorus pentoxide (Table S2, entries [16][17][18][19][20][21][22][23][24][25][26][27][28].…”

“…[26] Stirling et al have recently demonstrated that when performing the ATH of a 1-alkyl-substituted DHIQ (6,7-dimethoxy- [26] Stirling et al have recently demonstrated that when performing the ATH of a 1-alkyl-substituted DHIQ (6,7-dimethoxy-…”

Experimental and Theoretical Perspectives of the Noyori-Ikariya Asymmetric Transfer Hydrogenation of Imines

“…The reaction conditions were adapted from our previous study [44]. [b] The ee values were determined by employing a GC method reported by us [45].…”