Identification of a key intermediate in the asymmetric Appel process: one pot stereoselective synthesis of P-stereogenic phosphines and phosphine boranes from racemic phosphine oxides

Rajendran, Kamalraj V.; Gilheany, Declan G.

doi:10.1039/c2cc34136k

Cited by 53 publications

(37 citation statements)

References 41 publications

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“…The chemistry of the TPPO/(COCl) 2 combination originally reported in 1977 by Fukui. Then this reaction exploited by Denton and co‐workers in Apple reaction and other reactions under Apple condition, and Gilheany also used it to the research of phosphine oxides reductions …”

Section: Introductionmentioning

confidence: 99%

A high‐efficient method for the amidation of carboxylic acids promoted by triphenylphosphine oxide and oxalyl chloride

Jiang

Niu

et al. 2017

Heteroatom Chemistry

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Section: Introductionmentioning

confidence: 99%

A high‐efficient method for the amidation of carboxylic acids promoted by triphenylphosphine oxide and oxalyl chloride

Jiang

Niu

et al. 2017

Heteroatom Chemistry

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“…[14] Alternatively, hydride reduction of 4 (path e) leads to enantioenriched 2. [13,15] We have recently been working on the two principal limitations of this approach. First, the desirable stereochemical outcome of at least 90 % ee for the product oxides had not been attained in auxiliary screening.…”

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confidence: 99%

“…We have recently described [13] an NMR-based method for the determination of the de of the crucial DAPS intermediates 4, and we have now correlated this value with the ultimate ee value. Thus, racemic oxides 1 a-d were reacted with oxalyl chloride to give salts 3 a-d, which were then treated with a solution of (À)-menthol at À82 8C (Scheme 2).…”

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confidence: 99%

Turning Regioselectivity into Stereoselectivity: Efficient Dual Resolution of P‐Stereogenic Phosphine Oxides through Bifurcation of the Reaction Pathway of a Common Intermediate

et al. 2014

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Synthetic routes that provide facile access to either enantiomeric form of a target compound are particularly valuable. The crystallization-free dual resolution of phosphine oxides that gives highly enantioenriched materials (up to 94 % ee) in excellent yields is reported. Both enantiomeric oxides have been prepared from a single intermediate, (RP )-alkoxyphosphonium chloride, which is formed in the course of a selective dynamic kinetic resolution using a single enantiomer of menthol as the chiral auxiliary. The origin of the dual stereoselectivity lies in bifurcation of the reaction pathway of this intermediate, which works as a stereochemical railroad switch. Under controlled conditions, Arbuzov-type collapse of this intermediate proceeds through CO bond fission with retention of the configuration at the phosphorus center. Conversely, alkaline hydrolysis of the PO bond leads to the opposite SP enantiomer.

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“…[28][29][30][31][32][33] Moreover, the costs of such separations may be decreased by using a supercritical fluid as the mobile phase, which complements the time efficiency of chromatographic separations with cost efficiency. [40][41][42][43][44] However, many enantioseparation methods developed for chiral phosphine oxides comprise classical resolutions. Many methods based on the formation of covalent diastereomers, diastereomeric salts, or diastereomeric complexes were elaborated for P-chiral phosphine oxides.…”

Section: Introductionmentioning

confidence: 99%

The resolution of acyclic P‐stereogenic phosphine oxides via the formation of diastereomeric complexes: A case study on ethyl‐(2‐methylphenyl)‐phenylphosphine oxide

et al. 2018

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As an example of acyclic P-chiral phosphine oxides, the resolution of ethyl-(2-methylphenyl)-phenylphosphine oxide was elaborated with TADDOL derivatives, or with calcium salts of the tartaric acid derivatives. Besides the study on the resolving agents, several purification methods were developed in order to prepare enantiopure ethyl-(2-methylphenyl)-phenylphosphine oxide. It was found that the title phosphine oxide is a racemic crystal-forming compound, and the recrystallization of the enantiomeric mixtures could be used for the preparation of pure enantiomers. According to our best method, the (R)-ethyl-(2-methylphenyl)-phenylphosphine oxide could be obtained with an enantiomeric excess of 99% and in a yield of 47%. Complete racemization of the enantiomerically enriched phosphine oxide could be accomplished via the formation of a chlorophosphonium salt. Characterization of the crystal structures of the enantiopure phosphine oxide was complemented with that of the diastereomeric intermediate. X-ray analysis revealed the main nonbonding interactions responsible for enantiomeric recognition.

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Identification of a key intermediate in the asymmetric Appel process: one pot stereoselective synthesis of P-stereogenic phosphines and phosphine boranes from racemic phosphine oxides

Cited by 53 publications

References 41 publications

A high‐efficient method for the amidation of carboxylic acids promoted by triphenylphosphine oxide and oxalyl chloride

A high‐efficient method for the amidation of carboxylic acids promoted by triphenylphosphine oxide and oxalyl chloride

Turning Regioselectivity into Stereoselectivity: Efficient Dual Resolution of P‐Stereogenic Phosphine Oxides through Bifurcation of the Reaction Pathway of a Common Intermediate

The resolution of acyclic P‐stereogenic phosphine oxides via the formation of diastereomeric complexes: A case study on ethyl‐(2‐methylphenyl)‐phenylphosphine oxide

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