Preparation of the Enantiomers of Compounds Containing Chiral Phosphorus Centers

Valentine, Donald

doi:10.1016/b978-0-12-507704-0.50008-8

Cited by 18 publications

(4 citation statements)

References 175 publications

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“…Such ligands are usually prepared by exchange reactions between a chiral amine and a chlorophosphine or a dialkylaminophosphine as a trivalent phosphorus precursor. , Diastereomerically pure aminophosphine derivatives bearing also chirality at the phosphorus atom have been obtained in a similar way via highly diastereoselective exchange reactions, in which chirality is transmitted from amine to phosphorus. − However, literature offers very rare examples of enantiomerically pure aminophosphines with the phosphorus atom as the single chirogenic center. In their pioneering works, Horner and Jordan prepared enantiomerically enriched diethylaminoethylphenylphosphine by electrochemical reduction or cyanolysis of the corresponding resolved amidophosphonium salts . These phosphinous amides proved to be configurationally stable but very sensitive to oxidation.…”

Section: Introductionmentioning

confidence: 99%

Chromatographic Resolution, Solution and Crystal Phase Conformations, and Absolute Configuration of tert-Butyl(dimethylamino)phenylphosphine−Borane Complex

et al. 2006

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The enantiomers of tert-butyl(dimethylamino)phenylphosphine-borane complex 2 have been separated by HPLC using cellulose tris-p-methylbenzoate as chiral stationary phase. The borane protection could be removed without racemization and the P-configuration of the free aminophosphine 1 has shown to be stable in solution. Infrared (IR) and vibrational circular dichroism (VCD) spectra have been measured in CD2Cl2 solution for both enantiomers. B3LYP/6-31+G(d) DFT calculations allowed a prediction that complex (S)-2 exists as three conformers in equilibrium and computed population-weighted IR and VCD spectra. Predicted and experimental IR and VCD spectra compared very well and indicate that enantiomer (+)-2 has the S absolute configuration. This assignment has been confirmed by an X-ray diffraction study on a single crystal of (+)-2. The crystal structure of enantiomerically pure 2 appears to be very close to the most stable computed conformer which proved to be predominant in solution.

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Section: Introductionmentioning

confidence: 99%

Chromatographic Resolution, Solution and Crystal Phase Conformations, and Absolute Configuration of tert-Butyl(dimethylamino)phenylphosphine−Borane Complex

et al. 2006

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“…Although several phosphorothioates had been resolved through fractional crystallization of the alkaloid salts of cinchonidine, -phenylethylamine, quinine, brucine, and strychnine (15), only scant examples report the resolution of phosphorodithioates with alkaloids. Since an efficient synthesis of malathion enantiomers was established, alkaloid resolution of the stereogenic phosphorus should be possible.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, absolute configuration, and analysis of malathion, malaoxon, and isomalathion enantiomers

Berkman¹,

Thompson²,

Perrin³

1993

Chem. Res. Toxicol.

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Syntheses of the enantiomers of malathion, malaoxon, and isomalathion are reported herein. Malathion enantiomers were prepared from (R)- or (S)-malic acid in three steps. Enantiomers of malathion were converted to the corresponding enantiomers of malaoxon in 52% yield by oxidation with monoperoxyphthalic acid, magnesium salt. The four isomalathion stereoisomers were prepared via two independent pathways using strychnine to resolve the asymmetric phosphorus moiety. The absolute configurations of the four stereoisomers of isomalathion were determined by X-ray crystallographic analysis of an alkaloid salt precursor. A high-performance liquid chromatography technique was developed to resolve the four stereoisomers of isomalathion, and to determine their stereoisomeric ratios.

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“…Enantiomerism of main group hetero elements has been investigated thoroughly for compounds with stereogenic sulfur [ 1 ], phosphorus [ 2 ], nitrogen [ 3 ] and silicon atoms [ 4 ]. By comparison, stereogenic tetrahedral-coordinated boron has been studied to a much lesser extent.…”

Section: Introductionmentioning

confidence: 99%

Stereogenic boron in 2-amino-1,1-diphenylethanol-based boronate–imine and amine complexes

Schlecht¹,

Frank

Braun

2011

Beilstein J. Org. Chem.

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SummaryRacemic boronate–imine and boronate–amine complexes 8 and 10, both featuring a stereogenic boron atom were synthesized from 2-amino-1,1-diphenylethanol (5) and characterized by crystal structure analyses. Proof of enantiomerism at the boron center for the novel boronate–amine complex 10 was established by separation of the enantiomers. Racemization barriers were found to be in the same range for both amine and imine complexes (100–110 kJ/mol).

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Preparation of the Enantiomers of Compounds Containing Chiral Phosphorus Centers

Cited by 18 publications

References 175 publications

Chromatographic Resolution, Solution and Crystal Phase Conformations, and Absolute Configuration of tert-Butyl(dimethylamino)phenylphosphine−Borane Complex

Chromatographic Resolution, Solution and Crystal Phase Conformations, and Absolute Configuration of tert-Butyl(dimethylamino)phenylphosphine−Borane Complex

Synthesis, absolute configuration, and analysis of malathion, malaoxon, and isomalathion enantiomers

Stereogenic boron in 2-amino-1,1-diphenylethanol-based boronate–imine and amine complexes

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