Vereinfachte Synthese von Bis(triphenylphosphoranyliden)methan

Appel, Rolf; Knoll, Fritz; Schöler, Heinfried; Wihler, Horst‐Dieter

doi:10.1002/ange.19760882218

Cited by 42 publications

(19 citation statements)

References 8 publications

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“…Compound 1 was prepared from (ClC{PPh 3 } 2 )Cl and P(NMe 2 ) 3 according to a modified literature procedure. [35] B 2 H 6 was prepared as described previously. [36] CCDC-736303 (for 2), -736304 (for 2·THF), -737305 (for 3·THF), -736306 (for 4), and -736307 (for 5·DME) contain the supplementary crystallographic data for this paper.…”

Section: Methodsmentioning

confidence: 99%

Carbodiphosphorane C(PPh₃)₂as a Single and Twofold Lewis Base with Boranes: Synthesis, Crystal Structures and Theoretical Studies on [H₃B{C(PPh₃)₂}] and [{(μ‐H)H₄B₂}{C(PPh₃)₂}]⁺

et al. 2009

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The donor‐acceptor complex [(H3B){C(PPh3)2}] (2) has been synthesized by treating B2H6 with C(PPh3)2 and its geometry determined by X‐ray structure analysis. Treatment of 2 with DME yields the complex [{(μ‐H)H4B2}{C(PPh3)2}][B2H7] (4), which has also been isolated and structurally characterized. Compound 4 is the first complex of a carbodiphosphorane where the carbon donor atom binds with its two‐electron lone pairs to two main‐group Lewis acids larger than protons. This reaction is likely to occur via initial formation of [(H3B)2{C(PPh3)2}] (6), which subsequently reacts with B2H6, with loss of a hydride, to yield 4. Quantum chemical calculations of 2, 4+ and 6 show that the carbon–boron bonds in these complexes are very strong, and analysis of the bonding situation using the EDA, NBO and AIM methods reveals typical bonding patterns between the divalent carbon(0) moieties and one or two Lewis acids. The carbon donor atom of the carbodiphosphorane moiety remains strongly negatively charged even in the cation 4+. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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Section: Methodsmentioning

confidence: 99%

Carbodiphosphorane C(PPh₃)₂as a Single and Twofold Lewis Base with Boranes: Synthesis, Crystal Structures and Theoretical Studies on [H₃B{C(PPh₃)₂}] and [{(μ‐H)H₄B₂}{C(PPh₃)₂}]⁺

et al. 2009

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“…When the halogen compound (37) is reacted with (30), the phosphonium salts (38) (42) to give the phosphoranes (44), which rearrange to the acylamidephosphoranes (45) via an 0-N acyl migration. With gentle warming a further acyl group migration from the N-atom to the ylid carbon follows with a simultaneous shift of the proton from carbon to nitrogen.…”

Section: B Trimethylsilylated Ylidsmentioning

confidence: 99%

Old and new ylid chemistry

Bestmann¹

1980

Pure and Applied Chemistry

117

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A. The mechanism of the Wittig reaction is re-interpreted on the basis of new experimental and theoretical results. B. Reactions of trimethylsilylated phosphorus ylides are described. They allow a reversal of the stereochemistry of the Wittig reaction. C. The preparative possibilities of the reaction of N-phenyl-ketenylidenetriphenylphosphorane with carbon acids are presented and the synthesis of the tetramer of phenyl isonitrile is reported. D. The results of investigations into the reactions of Hexaphenylcarbodiphosphorane are presented. A. The Wittig Reaction Detailed investigations have led us to propose a new mechanism for the Wittig reaction.123 Ylides, (1), and aldehydes, (2), combine to give oxaphosphetanes, (3), in which the 0-atom occupies an apical position on the pentavalent phosphorus and in which the substituents on the four membered ring are B to one another. Cleavage of the original. ylid C-P bond, which is necessary for formation of the olefin, requires a ligand reorganisation process (pseudorotation) which brings this bond to an apical position,The opening of the C-P bond to give the betain (5) occurs during or after the conversion to the trigonal bipyramidal structure (u).The electronic nature of the substituents R1 and R2 in (5) is instrumental in determining the stereochemistry of the product olef in. When R1 phenyl electron donating R2 substituents cause a very fast elimination of the phosphine oxide, giving B olefins (7). Electron-withdrawing R2 groups (R1phenyl) extend the lifetime of (5), which can now isomerise to the thermodynamically more stable (6), from which phosphine oxide elimination gives E-olef ins (8). If the ligands R1 on phosphorus are electron-donating the rate of the phosphine oxide elimination is also decreased. In this case strongly increased formation of E-olefins is observed, compared to R1C6H5, even when R2 is an electron donor.

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“…The type I compound with A = Cl + , the salt (ClC{PPh 3 } 2 )Cl (1), plays the unique role as a key to the carbone C(PPh 3 ) 2 and is easily accessible in high yield from PPh 3 and CCl 4 . [12] The cation (ClǟC{PPh 3 } 2 ) + is isoelectronic to the neutral addition compound SeǟC(PPh 3 ) 2 reported earlier by Schmidbaur. The selenium atom was found to be nucleophilic and methylation gives the cation (MeSeǟC{PPh 3 } 2 )…”

Section: Scheme 1 Coordination Modes Of Carbones CL 2 To Lewis Acids Amentioning

confidence: 88%

Contribution to the Chemistry of (ClC{PPh₃}₂)Cl, a Precursor of the Carbodiphosphorane C(PPh₃)₂

Petz

Neumüller

2013

Zeitschrift anorg allge chemie

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Vereinfachte Synthese von Bis(triphenylphosphoranyliden)methan

Abstract: Verbindungen des Typs R3PCPR3 abstrahieren aufgrund ihres ausgeprägten Ylidcharakters begierig Protonen und Halogen. Für ihre Synthese wurde jetzt ein einfaches Verfahren gefunden, das in der Entchlorierung von (1) besteht.magnified image

Cited by 42 publications

References 8 publications

Carbodiphosphorane C(PPh₃)₂as a Single and Twofold Lewis Base with Boranes: Synthesis, Crystal Structures and Theoretical Studies on [H₃B{C(PPh₃)₂}] and [{(μ‐H)H₄B₂}{C(PPh₃)₂}]⁺

Carbodiphosphorane C(PPh₃)₂as a Single and Twofold Lewis Base with Boranes: Synthesis, Crystal Structures and Theoretical Studies on [H₃B{C(PPh₃)₂}] and [{(μ‐H)H₄B₂}{C(PPh₃)₂}]⁺

Old and new ylid chemistry

Contribution to the Chemistry of (ClC{PPh₃}₂)Cl, a Precursor of the Carbodiphosphorane C(PPh₃)₂

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Vereinfachte Synthese von Bis(triphenylphosphoranyliden)methan

Abstract: Verbindungen des Typs R3PCPR3 abstrahieren aufgrund ihres ausgeprägten Ylidcharakters begierig Protonen und Halogen. Für ihre Synthese wurde jetzt ein einfaches Verfahren gefunden, das in der Entchlorierung von (1) besteht.magnified image

Cited by 42 publications

References 8 publications

Carbodiphosphorane C(PPh3)2as a Single and Twofold Lewis Base with Boranes: Synthesis, Crystal Structures and Theoretical Studies on [H3B{C(PPh3)2}] and [{(μ‐H)H4B2}{C(PPh3)2}]+

Carbodiphosphorane C(PPh3)2as a Single and Twofold Lewis Base with Boranes: Synthesis, Crystal Structures and Theoretical Studies on [H3B{C(PPh3)2}] and [{(μ‐H)H4B2}{C(PPh3)2}]+

Old and new ylid chemistry

Contribution to the Chemistry of (ClC{PPh3}2)Cl, a Precursor of the Carbodiphosphorane C(PPh3)2

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Carbodiphosphorane C(PPh₃)₂as a Single and Twofold Lewis Base with Boranes: Synthesis, Crystal Structures and Theoretical Studies on [H₃B{C(PPh₃)₂}] and [{(μ‐H)H₄B₂}{C(PPh₃)₂}]⁺

Carbodiphosphorane C(PPh₃)₂as a Single and Twofold Lewis Base with Boranes: Synthesis, Crystal Structures and Theoretical Studies on [H₃B{C(PPh₃)₂}] and [{(μ‐H)H₄B₂}{C(PPh₃)₂}]⁺

Contribution to the Chemistry of (ClC{PPh₃}₂)Cl, a Precursor of the Carbodiphosphorane C(PPh₃)₂