Extraordinary deshielding of 31P in phosphines of the syn-7-phosphanorbornene system

Quin, Louis D.; Mesch, Keith A.

doi:10.1039/c39800000959

Cited by 25 publications

(6 citation statements)

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“…In view of the reaction conditions, a phosphinidene mechanism is excluded. The initial attack at phosphorus by the nucleophile likely produces an anionic pentacoordinate phosphorus species that undergoes a reductive elimination of dimethylnaphthalene . The hydrolysis of the P−O t Bu bond probably takes place during the workup.…”

Section: Resultsmentioning

confidence: 99%

2,3-Benzo-7-phosphanorbornadiene Complexes: Synthesis and Chemistry

2005

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The reaction of benzyne with 3,4-dimethylphosphole pentacarbonylmolybdenum complexes affords the corresponding 2,3-benzo-7-phosphanorbornadiene complexes through [4+2] cycloaddition. The condensation takes place on the less hindered side of the phosphole ring corresponding to the phosphorus substituent as shown by the X-ray crystal structure analysis of the phenyl derivative (2). The strain at the bridge of 2 (C−P−C angle ca. 80°) induces a variety of splitting reactions. Upon decomplexation by dppe at 110 °C in toluene, phenylphosphinidene is generated and recovered as phenylphosphine. Upon sulfurization under the same conditions, [PhPS2] is formed and trapped as a [4+2] adduct with 2,3-dimethylbutadiene. Potassium tert-butylate attacks the bridge in THF at −78 °C and, after methylation and hydrolytic workup, yields [Ph(Me)P(OH)Mo(CO)5].

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Section: Resultsmentioning

confidence: 99%

2,3-Benzo-7-phosphanorbornadiene Complexes: Synthesis and Chemistry

2005

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“…The Diels–Alder reactions of P(IV) derivatives of phosphole have attracted the attention of experimental and computational chemists because such reactions form a 7-phosphanorbornene moiety that holds unique properties of its P-center. − The significance of the 7-phosphanorbornene derivatives was explained by Quin, Mathey et al, in fragmentation-related phosphorylation reactions, , complexations, − and in refunctionalization − including deoxygenations. − Westheimer first reported the preparation of P(IV) derivatives of phosphole, which was further explored for the synthesis of the dimers of phosphole derivatives including oxides, sulfides, and quaternary salts. − …”

Section: Introductionmentioning

confidence: 99%

Probing the Structural and Electronic Effects on the Origin of π-Facial Stereoselectivity in 1-Methylphosphole 1-Oxide Cycloadditions and Cyclodimerization

2018

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We have examined the π-facial stereoselectivity in the Diels–Alder reactions of phosphole oxides computationally. The experimentally observed syn-cycloadditions have been rationalized with the Cieplak model and distortion–interaction model. The natural bond orbital analysis suggests that the hyperconjugative interactions are energetically preferred between the antiperiplanar methyl group present in the −P=O unit and the developing incipient (−C–C−) bond in syn-adducts in accordance with the Cieplak model. The distortion–interaction analysis carried out for syn and anti transition states of Diels–Alder reactions of 1-substituted phosphole 1-oxide with different dienophiles reveals that the syn selectivity is favored by distortions and interaction energies compared with the anti selectivity. The formation of a syn adduct is also stabilized by the π CC –σ* PO orbital interaction, and the repulsive n−π interaction destabilizes the anti adduct that leads to the 7.0 kcal/mol thermodynamic preference for the former adduct. Furthermore, the distortion–interaction model rationalizes the formation of stereospecific products in these Diels–Alder reactions, which however is not explicable with the much-debated Cieplak model.

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“…[1] Besides simple modifications of the phosphole ring substituents, three main transformations giving access to other classes of phosphorus derivatives are known: these are [4ϩ2] cycloaddition reactions at the dienic system, which afford 7-phosphanorbornenes [2,3] or 7-phosphanorbornadiene [4] derivatives; [1,5] sigmatropic shifts of the aryl, vinyl, or other labile phosphorus substituents around the phosphole nucleus, which lead to 1-phosphanorbornadienes; [5] and finally, the reactivity of either phospholes themselves or phospholyl anions towards suitable transition metal derivatives, which affords an easy access to phosphacyclopentadienyl complexes and phosphametallocenes. [6,7] Despite the wide synthetic potential of phosphole chemistry, the use of chiral species as synthetic tools has barely been considered.…”

Section: Introductionmentioning

confidence: 99%

Optically Active Phospholes: Synthesis and Use as Chiral Precursors for Phosphinidene and Phosphaferrocene Complexes

Sava

Marinetti

Ricard

et al. 2002

Eur. J. Inorg. Chem.

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Phospholes bearing chiral menthyl, myrtanyl, and (4-isopropyloxazolino)phenyl groups at the phosphorus atom were prepared. They were used as precursors for 7-phosphanorbornadienes and phosphinidene complexes. Unexpectedly, the [(4-isopropyloxazolino)phenyl]phosphinidene gave an intramolecular adduct with the imine moiety, which behaved as a 1,3-dipole in cycloaddition reactions. This afforded a new,

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Extraordinary deshielding of 31P in phosphines of the syn-7-phosphanorbornene system

Cited by 25 publications

References 0 publications

2,3-Benzo-7-phosphanorbornadiene Complexes: Synthesis and Chemistry

2,3-Benzo-7-phosphanorbornadiene Complexes: Synthesis and Chemistry

Probing the Structural and Electronic Effects on the Origin of π-Facial Stereoselectivity in 1-Methylphosphole 1-Oxide Cycloadditions and Cyclodimerization

Optically Active Phospholes: Synthesis and Use as Chiral Precursors for Phosphinidene and Phosphaferrocene Complexes

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