Phosphororganische verbindungen IXL zum sterischen verlauf der desoxygenierung von tertiären phosphinoxyden zu tertiären phosphinen mit trichlorsilan

Horner, L.; Balzer, Wolf‐Dieter

doi:10.1016/s0040-4039(01)83990-3

Cited by 115 publications

(60 citation statements)

References 5 publications

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“…However, we were unable to reduce the phosphane oxide to its phosphane. The usual conditions of AlH 3 , [12] HSiCl 3 [13] and LiAlH 4 [14,15] (at room temperature) failed to reduce the oxide 4. The phosphane oxide responded to more persuasive methods (LiAlH 4 in refluxing THF) with a debenzylation to give the phosphinous acid 6 (Scheme 2).…”

Section: Synthesis Of Racemic Phosphane Oxide and Boranementioning

confidence: 97%

Synthesis of Racemic and Enantiomerically Pure (R,R,R*)‐Tris(α‐methylbenzyl)phosphane − X‐ray Crystal Structures of the Phosphane Oxides and Borane Complexes

Wyatt¹,

Eley²,

Charmant³

et al. 2003

Eur J Org Chem

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An asymmetric synthesis of C3‐symmetric phosphane 1 has been achieved. Two of the α‐methylbenzyl groups were introduced as nucleophiles (using an α‐methylbenzyl Grignard reagent), and asymmetry was introduced by resolution using (R)‐α‐methylbenzylamine. The final α‐methylbenzyl group was introduced as an electrophile (α‐methylbenzyl iodide) in a modestly selective reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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Section: Synthesis Of Racemic Phosphane Oxide and Boranementioning

confidence: 97%

Synthesis of Racemic and Enantiomerically Pure (R,R,R*)‐Tris(α‐methylbenzyl)phosphane − X‐ray Crystal Structures of the Phosphane Oxides and Borane Complexes

Wyatt¹,

Eley²,

Charmant³

et al. 2003

Eur J Org Chem

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“…Current mechanistic understanding about the reactions of phosphine oxides and sulfides with chlorosilanes originates from the work of Horner 11 and Mislow. 12−14 The generally accepted mechanism for the reduction of an acyclic phosphine oxide by trichlorosilane (which proceeds with predominant retention of stereochemistry) 11,12 is shown in Scheme 2a.…”

Section: ■ Backgroundmentioning

confidence: 99%

Theoretical Investigation of the Mechanisms and Stereoselectivities of Reductions of Acyclic Phosphine Oxides and Sulfides by Chlorosilanes

Krenske

2012

J. Org. Chem.

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Computational studies were performed to explain the highly varied stereoselectivities obtained in the reductions of acyclic phosphine oxides and sulfides by different chlorosilanes. The reductions of phosphine oxides by HSiCl(3), HSiCl(3)/Et(3)N, and Si(2)Cl(6) and the reductions of phosphine sulfides by Si(2)Cl(6) (all in benzene) were explored by means of B3LYP, B3LYP-D, and SCS-MP2 calculations. For the reductions of phosphine oxides by HSiCl(3), the calculations support the mechanism proposed by Horner in which a hydride is transferred from silicon to phosphorus through a four-centered, frontside transition state. This mechanism leads to retention of stereochemistry at phosphorus. For the other three reductions, two classes of mechanisms were explored. Phosphorane-based mechanisms that were previously proposed by Mislow and involve SiCl(3)(-) were compared with novel alternative mechanisms that involve nonionic rearrangement processes. In one of these, donor-stabilized SiCl(2) is formed as an intermediate. The calculations support a phosphorane-based mechanism for the reductions of phosphine oxides by HSiCl(3)/Et(3)N and Si(2)Cl(6) (which proceed with inversion) but favor the rearrangement pathways for the reductions of phosphine sulfides by Si(2)Cl(6) (which proceed with retention).

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“…Therefore we applied a reduction protocol to phosphane oxide 6 using trichlorosilane and triethylamine, which is known to lead to inversion of the configuration at the phosphorus. [13][14][15] Complete conversion was verified by 31 P NMR spectroscopy. The 31 P NMR peak of starting phosphane oxide 6 at δ = 28.5 ppm had disappeared completely in favour of a peak at -7.3 ppm, corresponding to the phosphane.…”

Section: Resultsmentioning

confidence: 99%

“…We tentatively attribute this fact to a rapid homeomorphic isomerisation in solution, [19] which is made possible by the long and flexible arms of the macrobicyclic cage. The derivative phosphane-borane complex 7 was synthesised from phosphane oxide 6 via reduction with tri- chlorosilane proceeding with retention of the configuration at the phosphorus, [12][13][14] and subsequent quenching with borane-tetrahydrofuran complex (Scheme 3). [13] Scheme 3.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Derivatisation and Structural Characterisation of a New Macrobicyclic Phosphane Oxide Cryptand

2008

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Phosphororganische verbindungen IXL zum sterischen verlauf der desoxygenierung von tertiären phosphinoxyden zu tertiären phosphinen mit trichlorsilan

Cited by 115 publications

References 5 publications

Synthesis of Racemic and Enantiomerically Pure (R,R,R*)‐Tris(α‐methylbenzyl)phosphane − X‐ray Crystal Structures of the Phosphane Oxides and Borane Complexes

Synthesis of Racemic and Enantiomerically Pure (R,R,R*)‐Tris(α‐methylbenzyl)phosphane − X‐ray Crystal Structures of the Phosphane Oxides and Borane Complexes

Theoretical Investigation of the Mechanisms and Stereoselectivities of Reductions of Acyclic Phosphine Oxides and Sulfides by Chlorosilanes

Synthesis, Derivatisation and Structural Characterisation of a New Macrobicyclic Phosphane Oxide Cryptand

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Phosphororganische verbindungen IXL zum sterischen verlauf der desoxygenierung von tertiären phosphinoxyden zu tertiären phosphinen mit trichlorsilan

Cited by 115 publications

References 5 publications

Synthesis of Racemic and Enantiomerically Pure (R*,R*,R*)‐Tris(α‐methylbenzyl)phosphane − X‐ray Crystal Structures of the Phosphane Oxides and Borane Complexes

Synthesis of Racemic and Enantiomerically Pure (R*,R*,R*)‐Tris(α‐methylbenzyl)phosphane − X‐ray Crystal Structures of the Phosphane Oxides and Borane Complexes

Theoretical Investigation of the Mechanisms and Stereoselectivities of Reductions of Acyclic Phosphine Oxides and Sulfides by Chlorosilanes

Synthesis, Derivatisation and Structural Characterisation of a New Macrobicyclic Phosphane Oxide Cryptand

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Synthesis of Racemic and Enantiomerically Pure (R,R,R*)‐Tris(α‐methylbenzyl)phosphane − X‐ray Crystal Structures of the Phosphane Oxides and Borane Complexes

Synthesis of Racemic and Enantiomerically Pure (R,R,R*)‐Tris(α‐methylbenzyl)phosphane − X‐ray Crystal Structures of the Phosphane Oxides and Borane Complexes