Synthesis and first applications of a new family of chiral monophosphine ligand: 2,5-diphenylphosphospholanes

Guillen, Frédéric; Rivard, Michaël; Toffano, Martial; Legros, Jean‐Yves; Daran, Jean‐Claude; Fiaud, Jean‐Claude

doi:10.1016/s0040-4020(02)00554-9

Cited by 98 publications

(58 citation statements)

References 52 publications

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“…Preliminary experiments with the racemic mixture 8A C H T U N G T R E N N U N G (R+S) has already proved the principal usefulness of the cages as co-catalysts for the hydrogenation of C=C double bonds by H 2 gas in the presence of reactive Rh I complexes. [16] An equimolar mixture of catalytic amounts of 8A C H T U N G T R E N N U N G (R+S) and [{RhCl-…”

Section: Discussionmentioning

confidence: 99%

Cage Chirality of PC Cage Compounds: Highly Diastereoselective Formation of Diastereomeric P₅‐Deltacyclenes, Separation of Diastereomers, and Removal of the Chiral Auxiliary

Hofmann

Höhn

Heinemann

et al. 2009

Chemistry A European J

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An effective cyclic addition reaction of diastereomeric (R*)diphenyltin-3,5-di(tert-butyl)-1,2,4-triphosphole derivatives 6 a-c (R* = (-)-cis-myrtanyl (a), (-)-trans-myrtanyl (b), m-(2-bornyl-2-ene)phenyl (c) with two equivalents of tert-butylphosphaalkyne 1 leads to 1:1 mixtures of diastereomeric stannylated pentaphosphadeltacyclene derivatives 7 a-c with seven stereogenic centers in the cage unit. The (-)-cis-myrtanyl derivative 7 a could be separated into its diastereomers; destannylation of diastereomer 7 a(RR) led to the P-H cage 8 as a pure enantiomer. Circular dichroism (CD) spectroscopy of the pure diastereomer 7 a(RR) and the enantiomer 8 give evidence for identical stereoisomers of the P(5)-deltacyclene cage units and prove a strong dominance of the chiral cages over the chiral auxiliary groups with respect to their chiroptical properties. Absolute X-ray structure investigations of the majority of the compounds presented in the paper reveal the details of the stereochemistry of the asymmetric P-C cage units. In this paper we demonstrated for the first time a general preparative route to stereochemically fully defined asymmetric P-C cage compounds by separation of diastereomers and replacement of the chiral auxiliary group.

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Section: Discussionmentioning

confidence: 99%

Cage Chirality of PC Cage Compounds: Highly Diastereoselective Formation of Diastereomeric P₅‐Deltacyclenes, Separation of Diastereomers, and Removal of the Chiral Auxiliary

Hofmann

Höhn

Heinemann

et al. 2009

Chemistry A European J

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“…Two proposed retrosynthetic routes to these chiral phosphinites from phospholanic acid 5 [9] are depicted in Scheme 1. Retrosynthesis of phosphinite 1.…”

Section: Resultsmentioning

confidence: 99%

1‐Alkoxy‐2,5‐diphenylphospholane and ‐phospholanium Salts in Rhodium‐Catalyzed Asymmetric Hydrogenation

Galland¹,

Paris²,

Schlama³

et al. 2007

Eur J Org Chem

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“…COD was distilled and degassed; triethylamine was degassed. (2R,5R)-and (2S,5S)-1-hydroxy-1-oxo-2,5-diphenylphospholane, [37] (2R,5R)-2,5-dimethyl-1-phenylphospholane, [38] [RhA C H T U N G T R E N N U N G (cod) 2 ]BF 4 , [39] [AuClA C H T U N G T R E N N U N G (tht)], [40] [AuC 6 F 5 A C H T U N G T R E N N U N G (tht)], [41] [Au F MesA C H T U N G T R E N N U N G (tht)], [42] MAC, [43] MAA, [44] MAB, [45] and DMPI [46] were prepared according to literature procedures. All other chemicals were used as received from the supplier without further purification.…”

Section: Methodsmentioning

confidence: 99%

“…[24,25] Results and Discussion Synthesis and characterisation of the new chiral phospholanomethylamine ligands (5 a-i and 6 a-c): All chiral phospholane ligands reported herein have been synthesised via common key intermediates, the chiral 2,5-dimethyl (3) and 2,5-diphenyl ((S)-4 and (R)-4) bis(hydroxymethyl)phospholanium chloride salts, by modification of the method reported by Kemmitt et al [7] The starting materials, enantiopure secondary phosphanes (2R,5R)-2,5-dimethylphospholane (1), (2S,5S)-2,5-diphenylphospholane ((S)-2) and its enantiomer (R)-2, were prepared as described in the literature. [26,27] Due to their strong tendency to undergo oxidation, compounds such as these are often difficult to handle. However, this approach did not require the isolation of pure phospholanes 1 and (S)-2.…”

Section: Introductionmentioning

confidence: 99%

Stitching Phospholanes Together Piece by Piece: New Modular Di‐ and Tridentate Stereodirecting Ligands

Lloret‐Fillol¹,

Kruckenberg²,

Scherl³

et al. 2011

Chemistry A European J

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The modular one-pot synthesis of a large family of bi- and tridentate 2,5-dimethyl- and 2,5-diphenyl-substituted phospholanes employs air-stable chiral phospholanium chloride salts and primary amines or NH(4)Cl as starting materials. These were transformed into the C(2)-symmetric dimethyl- and diphenylphospholane ligands, which reacted with [Rh(cod)(2)]BF(4) (cod=1,5-cyclooctadiene) to yield the rhodium complexes [Rh(L)(cod)]BF(4) (L=bisphospholane ligands). The corresponding trisphospholane complexes, 11 and 12, were obtained in high yields (81 and 92%, respectively), and fully characterised by NMR spectroscopy, mass spectrometry and elemental analysis. Whilst in the C(3)-symmetric complex 11, containing the tridentate 2,5-dimethylphospholane, the ligand is bound symmetrically, different coordination behaviour was found for the diphenyl-substituted complex 12, in which the coordination of only two of the three phospholane moieties to the metal centre was observed. A DFT study at the B3PW91 level established minimum energy structures consistent with experimental findings in solution and in the solid state. The non-coordinated phospholane unit present in 12 allowed further modification of the complex through the coordination of Au(I)-X (X=Cl, C(6)F(5) and tris(trifluoromethyl)phenyl ((F)Mes)) fragments to the pendant phosphane. To investigate the potential of the new ligands, the enantioselective hydrogenation of a series of prochiral olefins as benchmark substrates, using isolated Rh complexes as catalysts, was studied. The substrates included methyl esters of three dehydro-α-acetamido acids and two itaconic acid derivatives. In general good to excellent enantioselectivities (of up to >99% ee) were observed. Ligand backbone modification by coordination of bulky Au-X substituents to the free phospholane unit in complex 12 led to an outstanding enhancement of the catalyst performance and there was a clear correlation between the properties of the complex periphery and the enantioselectivity.

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Synthesis and first applications of a new family of chiral monophosphine ligand: 2,5-diphenylphosphospholanes

Cited by 98 publications

References 52 publications

Cage Chirality of PC Cage Compounds: Highly Diastereoselective Formation of Diastereomeric P₅‐Deltacyclenes, Separation of Diastereomers, and Removal of the Chiral Auxiliary

Cage Chirality of PC Cage Compounds: Highly Diastereoselective Formation of Diastereomeric P₅‐Deltacyclenes, Separation of Diastereomers, and Removal of the Chiral Auxiliary

1‐Alkoxy‐2,5‐diphenylphospholane and ‐phospholanium Salts in Rhodium‐Catalyzed Asymmetric Hydrogenation

Stitching Phospholanes Together Piece by Piece: New Modular Di‐ and Tridentate Stereodirecting Ligands

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Synthesis and first applications of a new family of chiral monophosphine ligand: 2,5-diphenylphosphospholanes

Cited by 98 publications

References 52 publications

Cage Chirality of PC Cage Compounds: Highly Diastereoselective Formation of Diastereomeric P5‐Deltacyclenes, Separation of Diastereomers, and Removal of the Chiral Auxiliary

Cage Chirality of PC Cage Compounds: Highly Diastereoselective Formation of Diastereomeric P5‐Deltacyclenes, Separation of Diastereomers, and Removal of the Chiral Auxiliary

1‐Alkoxy‐2,5‐diphenylphospholane and ‐phospholanium Salts in Rhodium‐Catalyzed Asymmetric Hydrogenation

Stitching Phospholanes Together Piece by Piece: New Modular Di‐ and Tridentate Stereodirecting Ligands

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Product

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Cage Chirality of PC Cage Compounds: Highly Diastereoselective Formation of Diastereomeric P₅‐Deltacyclenes, Separation of Diastereomers, and Removal of the Chiral Auxiliary

Cage Chirality of PC Cage Compounds: Highly Diastereoselective Formation of Diastereomeric P₅‐Deltacyclenes, Separation of Diastereomers, and Removal of the Chiral Auxiliary