Intramolecular [3+2] Cycloaddition of a Nitrilium Phosphane Ylide Complex to theP-Phenyl Group of a Wittig Ylide

Hoffmann, Nils; Jones, Peter G.; Streubel, Rainer

doi:10.1002/1521-3773(20020402)41:7<1186::aid-anie1186>3.0.co;2-h

Cited by 4 publications

(1 citation statement)

References 23 publications

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“…In contrast to this, 1,2λ 3 -azaphospholenes V − IX (Scheme ) are still elusive species, because of a significant lack of synthetic strategies for these ring systems. For example, there are only two short communications on complexes having a 1,2λ 3 -azaphosphol-4-ene ( V ), , some on 1,2λ 3 -azaphosphol-3-enes ( VI )either free or in a P-ligated fashionand on 1,2λ 3 -azaphosphol-3-enes ( VII ). , Very recently, the latter, chiral so-called Wilke's-azaphospholene, has received increased attention in catalysis. , …”

Section: Introductionmentioning

confidence: 99%

1,2-Azaphosphol-5-ene Complexes through Metal-Assisted Synthesis

et al. 2006

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Thermal ring opening of {[2-bis(trimethylsilyl)methyl-3-phenyl-2H-azaphosphirene-κP]pentacarbonyltungsten(0)} (1) in toluene in the presence of 1-piperidino carbonitrile (2) and various mono-and disubstituted alkenes, i.e., ethyl acrylate (4), E-stilbene (6), fumaronitrile (7), and maleic anhydride (10), was investigated. Special emphasis was placed on the dependence of the regio-and stereoselectivity of the transiently formed nitrilium phosphane-ylide complex 3 on the electronic properties of the alkenes. Three-component reaction of 1, 2, and 4 yielded regioselectively a 1:1 mixture of the diastereomeric 4-ethoxycarbonyl-substituted 1,2-azaphosphol-5-ene complexes 5a,b; the constitution of 5a was unambiguously established by single-crystal X-ray diffraction. Whereas E-stilbene (6) gave no reaction with complex 3, fumaronitrile (7) reacted with transient 3 to furnish the diastereomeric 1,2-azaphosphol-5-ene complexes 8a,b together with the 2H-1,3,2-diazaphosphole complex 9; the product ratio of 2:1:1 was determined by 31 P{ 1 H} NMR spectroscopy. Reaction of 1, 2, and maleic anhydride (10) resulted in a complicated product mixture, whereby the constitution of the spirocyclic complexes 11a,b (bearing a 1,3,2-oxazaphosphol-3-ene moiety) is based on their NMR data. Further examination showed that the C-O double bond system of 10 did not participate in a [3+2] cycloaddition reaction if the thermal decomposition of complex 1 was carried out in neat benzonitrile, thus showing the preference of the transiently formed C-phenylsubstituted nitrilium phosphane-ylide complex 12 for the C-C double bond of 6: In this case, the bicyclic complexes 13a,b were formed exclusively.

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Section: Introductionmentioning

confidence: 99%

1,2-Azaphosphol-5-ene Complexes through Metal-Assisted Synthesis

et al. 2006

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A Novel N,P,C Cage Complex Formed by Rearrangement of a Tricyclic Phosphirane Complex: On the Importance of Non‐covalent Interactions

Nesterov

Espinosa

Schnakenburg

et al. 2014

Chemistry A European J

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The reaction of Li/Cl P-CPh3 phosphinidenoid tungsten(0) complex 2 with dimethylcyanamide afforded tricyclic phosphirane complex 4, an unprecedented rearrangement of which led to the novel N,P,C cage complex 6. On the basis of DFT calculations, formation and intramolecular [3+2] cycloaddition of the transient nitrilium phosphane ylide complex 3 to a phenyl ring of the triphenylmethyl substituent to give 4 is proposed. Furthermore, theoretical evidence for terminal N-amidinophosphinidene complex 7, formed by [2+1] cycloelimination from 4, is provided, and the role of the electronic structure and non-covalent interactions of intermediate 7 discussed.

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Copper(I) Chloride Initiated Decomposition of 7-Phosphanorbornadiene. Evidence for a Solvent-Assisted Catalytic Mechanism

2003

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Density functional theory is used to explore the mechanism of the copper(I)-chloride-catalyzed decomposition of W(CO)(5)-complexed 7-phosphanorbornadiene and the subsequent olefin trapping of the terminal phosphinidene complex. CuCl lowers the activation barrier by interacting directly with the breaking P-C bond. Contrary to the prevailing notion that a free terminal phosphinidene complex (W(CO)(5)=PR) is generated in the CuCl-catalyzed cheletropic elimination of the 7-phosphanorbornadiene-W(CO)(5) complex, the present mechanism suggests that CuCl is attached to the terminal phosphinidene. Furthermore, a "chloride shuttle" takes place where the chloride first migrates to the phosphorus center and then is returned back to the copper center by the incoming olefin in an S(N)2 reaction step. When the substituent on phosphorus is a phenyl group (R = Ph), the uncatalyzed reaction has an activation barrier of 17.9 kcal/mol, which is reduced by 10.9 kcal/mol on including the CuCl catalyst. The CuCl-catalyzed decomposition of 7-phosphanorbornadiene followed by olefin trapping of the terminal phosphinidene complex has a close parallel with the Cu(I)-catalyzed cyclopropanation reaction of diazoalkane. In both catalyzed reactions, copper(I) is coordinated to the phosphinidene/carbene as a Lewis acid, while a Lewis base is displaced from the phosphorus/carbon center as the olefin is added.

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Intramolecular [3+2] Cycloaddition of a Nitrilium Phosphane Ylide Complex to theP-Phenyl Group of a Wittig Ylide

Cited by 4 publications

References 23 publications

1,2-Azaphosphol-5-ene Complexes through Metal-Assisted Synthesis

1,2-Azaphosphol-5-ene Complexes through Metal-Assisted Synthesis

A Novel N,P,C Cage Complex Formed by Rearrangement of a Tricyclic Phosphirane Complex: On the Importance of Non‐covalent Interactions

Copper(I) Chloride Initiated Decomposition of 7-Phosphanorbornadiene. Evidence for a Solvent-Assisted Catalytic Mechanism

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