Polycyclic Group V ligands. III. 2,6,7-Trimethyl-4-methyl-2,6,7-triaza-1-phosphabicyclo[2.2.2]octane. A bidentate donor

Laube, B.; Bertrand, Richard; Casedy, G. A.; Compton, R. D.; Verkade, John G.

doi:10.1021/ic50047a046

Cited by 36 publications

(15 citation statements)

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“…An appealing approach to separating the factors leading to strong electrophile binding at phosphorus is to prepare an analogue to proazaphosphatranes that lacks an axial nitrogen. This strategy has been attempted synthetically by preparing compounds of the type P(RNCH 2 ) 3 CCH 3 (R = Me or i -Bu) (Figure A, 2 ). , Direct comparison of these aminophosphines with proazaphosphatranes is precluded by 2 being more pyramidal at phosphorus than is a proazaphosphatrane . An alternative approach is replacement of the axial nitrogen of P( i -BuNCH 2 CH 2 ) 3 N with a methine group to preserve the bicyclo[3.3.3]undecane structure (Figure , 3 ); however, a synthesis of this compound is unknown.…”

Section: Resultsmentioning

confidence: 99%

On Transannulation in Azaphosphatranes: Synthesis and Theoretical Analysis

et al. 2019

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A combined synthetic-theoretical study has been undertaken to determine the factors that influence transannulation in azaphosphatranes. The commonly used proazaphosphatrane P(i-BuNCH2CH2)3N and several of its oxidized congeners are used as model systems. The haloazaphosphatranes of P(i-BuNCH2CH2)3N were synthesized, including a rare fluoroazaphopshatrane, and used as references for computational investigations. Comparisons of the experimental and theoretical observations highlight the flexibility observed in transannulated atranes and the potential for multiple local energetic minima depending on the identity of the equatorial substituents for a given azaphosphatrane. Theoretical calculations also identify the role of the ethylene linker in azaphosphatrane bonding, the influence of transannulation on P–electrophile interactions, and the contribution of electrostatic interactions to transannulation.

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Section: Resultsmentioning

confidence: 99%

On Transannulation in Azaphosphatranes: Synthesis and Theoretical Analysis

et al. 2019

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“…'~An adduct with a BH, group on one of the N atoms of 8 was obtained by Verkade, but only after a first BH, group had been coordinated to the phosphorus site; however, it loses the N-coordinated borane group on attaining room temperature. 20 In 9, all the four P-sites readily accept BH, or Ni(CO),,. while the coordination of the N sites was never observed.8 A forced pyramidal configuration at nitrogen does not guarantee obtaining a stable adduct at nitrogen.…”

Section: Protonation and Alkylationmentioning

confidence: 99%

About the Coordination Chemistry of the Phosphorus-Nitrogen Entity

Riess

1986

Phosphorous and Sulfur and the Related Elements

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Triply coordinated trivalent nitrogen atoms are known to lose most or all of their Lewis donor capacity when bonded to a third or higher row element. It is shown here, in the case of P-bonded nitrogen atoms, that structural constraints which maintain the nitrogen atom in a pyramidal configuration can contribute much in preserving their basicity and/or nucleophilic character. In particular, nitrogen atoms apically bonded to 5-coordinated formally penta-or trivalent phosphorus atoms can display definite basicity. Examples of metal-and base-induced opening and closing of P-N bonds are also presented. The following unusual coordination modes and/or reaction issues are exemplified:where A can be-depending on the case-H+,CH~,BH,,BF, or a transition metal moiety, as for example CpMo(CO),CI or CpMo(CO),, etc. The factors that affect the rather variable P-N bond length are discussed.

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“…MeC(CH 2 NMe) 3 P and N(CH 2 CH 2 NMe) 3 P were prepared using literature methods. [44][45][46][47][48] Synthesis of MeC(CH 2 NMe) 3 PNSiMe 3 (1). Me 3 SiN 3 (0.723 mL, 5.45 mmol) was added to MeC(CH 2 NMe) 3 P (0.636 g, 3.63 mmol), and the mixture was heated at refluxing temperature for 3 h. Excess Me 3 SiN 3 was removed under vacuum.…”

Section: General Considerationsmentioning

confidence: 99%

Titanium complexes of amidophosphinimide ligands

Alhomaidan¹,

Beddie²,

Bai³

et al. 2009

Dalton Trans.

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The tripodal phosphines MeC(CH(2)NMe)(3)P and N(CH(2)CH(2)NMe)(3)P were converted to the corresponding phosphinimines and the corresponding Ti-complexes MeC(CH(2)NMe)(3)PNTiCpCl(2) and N(CH(2)CH(2)NMe)(3)PNTiCpCl(2) were prepared. These species were also alkylated to give the corresponding dimethyl derivatives. Preliminary attempts to utilize these species in the polymerization of ethylene with MAO as the activator resulted in all but negligible activity. An alternative synthetic approach utilizing the bis-phosphinimine (CH(2)(Me)NPtBu(2))(2) was developed to prepare (CH(2)(Me)NP(tBu(2))NSiMe(3))(2), (CH(2)(Me)NP(tBu(2))NH)(2) and subsequently [(CH(2)(Me)NP(tBu(2))N)(2)]Ti(NMe(2))(2) , [(CH(2)(Me)NP(tBu(2))N)(2)]TiCl(2) and [(CH(2)(Me)NP(tBu(2))N)(2)]TiMe(2). For comparison purposes the related species [tBu(2)(Me(2)N)PN](2)TiCl(2) and [tBu(2)(Me(2)N)PN](2)TiMe(2) were also prepared. Compounds, using 2 equiv. of [Ph(3)C][B(C(6)F(5))(4)] as the activator, resulted in moderate to good polymerization activities.

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Polycyclic Group V ligands. III. 2,6,7-Trimethyl-4-methyl-2,6,7-triaza-1-phosphabicyclo[2.2.2]octane. A bidentate donor

Cited by 36 publications

References 0 publications

On Transannulation in Azaphosphatranes: Synthesis and Theoretical Analysis

On Transannulation in Azaphosphatranes: Synthesis and Theoretical Analysis

About the Coordination Chemistry of the Phosphorus-Nitrogen Entity

Titanium complexes of amidophosphinimide ligands

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