Horner-Wittig reactions of β-aminoalkyl- and β-N-acylaminoalkyldiphenylphosphine oxides: synthesis of N-allyl amines and amides and 5-diphenylphosphinoyl-2-phenyl-5,6-dihydro-4H-1,3-oxazines

Cavalla, David; Cruse, W. B. T.; Warren, Stuart

doi:10.1039/p19870001883

Cited by 25 publications

(6 citation statements)

References 18 publications

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“…The formation of 4 is believed to result from initial basecatalysed isomerisation of the allyl-to the methylvinyl-phosphine, which then undergoes addition of the piperazino moiety, in accordance with comparable observations in the literature. 25,26 The coordination chemistry of 4 is entirely analogous to that of 1 and hence will be discussed elsewhere. 27…”

Section: Ligand Synthesesmentioning

confidence: 99%

Concise syntheses of tridentate PNE ligands and their coordination chemistry with palladium(ii) : a solution- and solid-state study

et al. 2006

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A straightforward methodology for the high-yielding synthesis of the di-functionalised phosphines {Ph2P(CH2)2NC4H8E, E = NMe (1), O (2), S (3)}via base-catalysed Michael addition is described. Reaction of the functionalised tertiary phosphines 1-3 with PdCl2(MeCN)2 affords complexes in which the ligands are bound in a tridentate fashion, namely [PdCl(kappa3-PNE)]Cl (6a, 8) as the predominant products. A kappa2-PN coordination mode was also identified crystallographically for ligand following its reaction with PdCl2(MeCN)2, which afforded [PdCl2(-kappa2-PN)] (6b) in ca. 5% yield. Conductivity studies of solutions of 6a are consistent with an ionic formulation, however the poor solubility of and precluded their study in a similar fashion. Analysis of bulk samples of [PdCl2(1)] (6) and [PdCl2(3)] (8) by 15N and 31P NMR spectroscopy in the solid state as consistent with exclusive tridentate binding of the PNE ligands. An X-ray crystallographic study has probed the coordination of in the unusual salt [PdCl(-kappa3-PNN)]2[Mg(SO4)2(OH2)4] (10) prepared by treating a methanolic solution of with excess MgSO4. No data could be obtained to support the transformation of 6a into 6b on addition of excess chloride. In contrast, 6a reacts regioselectively with the water-soluble phosphine Cy2PCH2CH2NMe3Cl to afford the cis-diphosphine complex cis-[PdCl(Cy2PCH2CH2NMe3Cl)(1-kappa2-PN)]Cl2 (9). Reaction of 1 with PdCl(Me)(COD) results in the formation of the kappa2-PN dichloride complex [PdCl(Me)(1-kappa(2)-PN)] (11). Attempts to prepare [Pd(Me)(MeCN)(-kappa2-PN)][PF6] (12) through reaction of 11 with NaPF6 in MeCN led to decomposition. Treatment of PdMe2(TMEDA) with 1 at low temperature initially affords [PdMe2(1-kappa2-NN)], which isomerises to afford [PdMe(2)(1-kappa(2)-PN)] (13); at temperatures greater than 10 degrees C complex 13 decomposes rapidly.

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Section: Ligand Synthesesmentioning

confidence: 99%

Concise syntheses of tridentate PNE ligands and their coordination chemistry with palladium(ii) : a solution- and solid-state study

et al. 2006

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“…Table contains details relating to data collection and structure solution and refinement, Table contains selected interatomic distances and angles for the structure of 2a . As is normally found for this class of compounds, , conformer ga is adopted by 2a − e in the solid state. The hydrogen bonding is determined by the O−P−C−C torsion angle.…”

Section: Resultsmentioning

confidence: 94%

“…In NMR studies on the conformational preferences of (2-hydroxyalkyl)phosphonates in solution, intramolecular hydrogen bonding was invoked to explain the preponderance of the conformer with a gauche orientation between the phosphoryl and the hydroxyl group and anti orientation between the former group and the alkyl group ( ga ) . The crystal structures of (2-hydroxyalkyl)phosphine oxides 1a − c have been elucidated solely to assign the configurations of the chiral centers . In these studies both intermolecular ( 1a,b ) 3a,c and intramolecular ( 1c ) 3b hydrogen bonding in the solid state have been observed.…”

Section: Introductionmentioning

confidence: 99%

Conformational Analysis of 2-Substituted Alkylphosphoryl Compounds. 4. Substituent Effect on the Nature of the Hydrogen Bonding in (2-Hydroxyalkyl)phosphoryl Systems

1998

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The extent to which solid state conformational and hydrogen bonding preferences of five (2-hydroxyalkyl)phosphoryl compounds 2a-e [R(1)(2)P(O)CH(2)CH(OH)R(2); 2a, R(1) = MeO, R(2) = Ph; 2b, R(1) = R(2) = Ph; 2c, R(1) = Ph, R(2) = Bu(t); 2d, R(1) = Me, R(2) = Ph; 2e, R(1) = Me, R(2) = Bu(t)] change upon dissolution has been investigated using X-ray crystallography, IR, and NMR spectroscopy. Intermolecular hydrogen bonding involving inversion-center-related cyclic dimers is shown to be a common solid state arrangement, with relatively small structural changes producing infinite chains. Intramolecular hydrogen bonded monomers are uncommon. Conflicting X-ray and IR evidence on the equivalence of hydrogen bonding in the dimeric structure of 2b in the solid state is discussed. The changes in hydrogen bonding occurring upon dissolution have been studied and evidence presented that an equilibrium between dimers and monomers is usually set up, which can become extensively shifted to a predominance of intramolecular hydrogen bonded monomers when bulky groups (R(1) and R(2)) are present. Conformational preferences are determined mainly by steric factors (the size of R(2)) and little influenced by changes in the nature of the hydrogen bonding or donation of electrons from the hydroxyl oxygen to vacant orbitals of the phosphorus atom. The extent of distortion from perfectly staggered geometries, upon which most conformational analyses are based, has been estimated to be 4 to 12 degrees for two of the compounds. Ab initio and molecular mechanics solvation studies have been used to explain NMR chemical shift trends of the alpha-methylene protons and the phosphorus nucleus. Large chemical shift differences between the alpha-methylene protons of diphenylphosphine oxides 2b and 2c in acetone-d(6) are attributed to the specific orientation of acetone-d(6) molecules toward one of the protons in the major conformer.

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“…We have previously investigated Horner-Wittig addition reactions of β-aminoand β-amido phosphine oxides. 10 Reaction of the dilithiated derivative of the amide 5 with ketones gave the anti diastereoisomer 6 in acceptable yield. Reaction with an aldehyde gave a mixture of diastereoisomers 7, differing only in the relative stereochemistry between the alcohol and phosphorus centers (Scheme 3).…”

Section: Resultsmentioning

confidence: 99%

Synthesis, X-ray crystal structures and Horner–Wittig addition reactions of some protected β-aminophosphine oxides

Feeder¹,

Fox²,

Medlock³

et al. 2002

J. Chem. Soc., Perkin Trans. 1

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Several protected β-aminophosphine oxides have been synthesised and investigated in the Horner-Wittig addition reaction. Crystal structures of an enantiomerically pure β-amino phosphine oxide and a Horner-Wittig addition product are presented. Horner-Wittig reactions were typically poorly stereoselective, although the ratio of diastereoisomers can be influenced by the addition of lithium bromide.

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Horner-Wittig reactions of β-aminoalkyl- and β-N-acylaminoalkyldiphenylphosphine oxides: synthesis of N-allyl amines and amides and 5-diphenylphosphinoyl-2-phenyl-5,6-dihydro-4H-1,3-oxazines

Cited by 25 publications

References 18 publications

Concise syntheses of tridentate PNE ligands and their coordination chemistry with palladium(ii) : a solution- and solid-state study

Concise syntheses of tridentate PNE ligands and their coordination chemistry with palladium(ii) : a solution- and solid-state study

Conformational Analysis of 2-Substituted Alkylphosphoryl Compounds. 4. Substituent Effect on the Nature of the Hydrogen Bonding in (2-Hydroxyalkyl)phosphoryl Systems

Synthesis, X-ray crystal structures and Horner–Wittig addition reactions of some protected β-aminophosphine oxides

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