Optically Active 1‐Deuterio‐1‐phenylethane – Preparation and Proof of Enantiopurity

Küppers, Julian; Rabus, Ralf; Wilkes, Heinz; Christoffers, Jens

doi:10.1002/ejoc.201900121

Cited by 12 publications

(22 citation statements)

References 23 publications

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“…Accordingly, the pharmaceuticals fendiline, clopidogrel, and rivastigmine were synthesized, which confirmed high levels of applicability. Recently, Christoffers and co‐workers exploited the catalytic chlorination with FPyr and BzCl for the synthesis of enantioenriched 1‐deutereo‐1‐phenylethane 23 , an agent for the elucidation of the stereochemistry of CH‐activating enzymes . Deuterodechlorination of the respective alkyl chloride with LiAlD 4 provided target compound 23 in 92 % ee under overall retention.…”

Section: Substrate Class Alcoholsmentioning

confidence: 99%

Lewis Base Catalysis Promoted Nucleophilic Substitutions – Recent Advances and Future Directions

Huy

2019

Eur J Org Chem

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Nucleophilic substitutions (S N ) account for the most essential and frequently applied chemical transformations. S Nreactions allow forging C-C, C-O, C-N and C-Cl bonds, for example, from natural abundant starting materials such as alcohols and carboxylic acids. Products of S N -reactions are ubiquitous and find inter alia applications as pharmaceuticals, plant protection agents and polymers. However, conventional S N -type approaches are restricted frequently by the necessity of hazardous reagents and by-products, a poor waste-balance and there- [a] 24 Scheme 23. Impact of the Lewis base PPh 3 on the Brønsted acid catalyzed synthesis of alkenes 31.

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Section: Substrate Class Alcoholsmentioning

confidence: 99%

Lewis Base Catalysis Promoted Nucleophilic Substitutions – Recent Advances and Future Directions

Huy

2019

Eur J Org Chem

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“…[13,26,31,32] Chiral derivatization approaches require molecule-specific development of the derivatizing agent as illustrated by a previous analysis of ethylbenzene-d1. [26] Both chiral derivatization and 2 H-NMR measurements in aligned media pose challenges for high-confidence AC determination. For example, strong temperature dependence of the deuterium quadrupole splitting in aligned media-including reversal of the enantiomer signatures-has been noted.…”

Section: Introductionmentioning

confidence: 99%

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

et al. 2022

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Fundamental to the synthesis of enantioenriched chiral molecules is the ability to assign absolute configuration at each stereogenic center, and to determine the enantiomeric excess for each compound. While determination of enantiomeric excess and absolute configuration is often considered routine in many facets of asymmetric synthesis, the same determinations for enantioisotopomers remains a formidable challenge. Here, we report the first highly enantioselective metal‐catalyzed synthesis of enantioisotopomers that are chiral by virtue of deuterium substitution along with the first general spectroscopic technique for assignment of the absolute configuration and quantitative determination of the enantiomeric excess of isotopically chiral molecules. Chiral tag rotational spectroscopy uses noncovalent chiral derivatization, which eliminates the possibility of racemization during derivatization, to perform the chiral analysis without the need of reference samples of the enantioisotopomer.

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“…Recently, the enantiopurity of ( S )‐(1‐ 2 H)ethylbenzene [( S )‐ 3 ] was determined by NMR spectroscopy after chiral derivatization with ( R )‐α‐phenethylamine (Scheme 2). [13] …”

Section: Introductionmentioning

confidence: 99%

“… Synthesis of bis‐sulfonamide 5 from (1‐ 2 H)ethylbenzene ( S )‐ 3 . Reagents: (a) ClSO 3 H, (b) ( R )‐PhCH(NH 2 )Me [13] …”

Section: Introductionmentioning

confidence: 99%

Enantiopure 2,9‐Dideuterodecane – Preparation and Proof of Enantiopurity

et al. 2021

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(R,R)‐ and (S,S)‐(2,9‐2H2)‐n‐Decane were prepared regio‐ and stereospecifically in 25–26 % yield over five steps from commercially available enantiopure (R)‐ and (S)‐propylene oxide, respectively. The synthetic procedure involved nucleophilic displacement of (R)‐ and (S)‐4‐toluenesulfonic acid 1‐methyl‐4‐pentenyl ester with LiAlD4 to furnish the respective (5‐2H)‐1‐hexenes. Subsequent olefin metathesis and reduction of the double bond furnished the title compounds. The optical purity of (R,R)‐ and (S,S)‐(2,9‐2H2)‐n‐decane could not be determined by chromatography or polarimetry. Therefore, (R,R)‐ and (R,S)‐(5‐2H)‐3‐hydroxy‐2‐hexanone were prepared from their respective hexenes by Wacker oxidation, followed by enantioselective α‐hydroxylation. The enantiopurity could then be determined by NMR spectroscopy because the stereospecifically deuterated hydroxyketones showed separated signals for the subterminal carbon atom (C‐5) in the 13C NMR spectrum.

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Optically Active 1‐Deuterio‐1‐phenylethane – Preparation and Proof of Enantiopurity

Cited by 12 publications

References 23 publications

Lewis Base Catalysis Promoted Nucleophilic Substitutions – Recent Advances and Future Directions

Lewis Base Catalysis Promoted Nucleophilic Substitutions – Recent Advances and Future Directions

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

Enantiopure 2,9‐Dideuterodecane – Preparation and Proof of Enantiopurity

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