Unusual rearrangement of σ-vinylpalladium complexes into η2-olefin complexes. The structure of (η2-1-triphenylphosphonium-2-carbomethoxyethylene)(triphenylphosphine)iodopalladate

Rybin, L. V.; Petrovskaya, E. A.; Rubinskaya, M.I.; Kuz'mina, L. G.; Struchkov, Yu. T.; Kaverin, V. V.; Koneva, N.Yu.

doi:10.1016/0022-328x(85)80110-8

Cited by 34 publications

(20 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact, examples of this type of isomerization reaction are very rare in literature. [29] Interestingly, by dissolving the crystals in CH 2 Cl 2 the same fluxional behavior as described before is observed, indicated by 31 P NMR spectroscopy. At the same time, the exact nature of the prepared pincer-palladium complexes at room temperature in solution thus remains elusive.…”

Section: Preparation Of Palladium Complexessupporting

confidence: 75%

Molecular‐Weight‐Enlarged Multiple‐Pincer Ligands: Synthesis and Application in Palladium‐Catalyzed Allylic Substitution Reactions

et al. 2009

View full text Add to dashboard Cite

Three different pincer ligand systems are synthesized via nucleophilic substitution reactions of polyaromatic benzyl bromides as support molecules and phenol derivatives as ligand precursors. Retention tests using a polymeric nanofiltration membrane show moderate to good retention in THF and CH(2)Cl(2). Concentration-dependent NMR spectroscopy gives no indication for the formation of aggregates in solution. The three ligand systems are active in both the allylic alkylation and allylic amination reactions and show high selectivity towards the linear trans products. An investigation of the kinetic parameters of the allylic amination reaction show that the reaction of cinnamyl acetate with morpholine is of zero order in cinnamyl acetate and of first order in morpholine. The order in catalyst is found to be one, and the rate constant k' is determined for a reaction under standard conditions. Moreover, one of the tri(pincer)-palladium complexes is used as soluble, molecular-weight-enlarged homogeneous catalyst in continuous allylic alkylation and amination reactions. The conversion of the allylic alkylation reaches a maximum of 30 %, while a maximum conversion of 80 % is reached in the allylic amination reaction. No palladium black was formed.

show abstract

Section: Preparation Of Palladium Complexessupporting

confidence: 75%

Molecular‐Weight‐Enlarged Multiple‐Pincer Ligands: Synthesis and Application in Palladium‐Catalyzed Allylic Substitution Reactions

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The rhodium−allenylphosphonium coordination exhibits Rh−C distances of 2.130(7) Å (Rh−C(1)) and 1.969(7) Å (Rh−C(2)), which agree well with those found in rhodium(I)−olefin complexes (mean values 2.10 Å) . The P(1)−C(1) bond length of 1.809(7) Å is close to that observed in W(η 5 -C 5 H 5 )(CO) 2 {η 2 -CH(PPh 3 )CHCN} (1.802(3) Å) 2a and is significantly greater than the values found for PC double bonds (for example, 1.640(6) Å in (CH 3 ) 3 PCH 2 ) 9 or for partial phosphorus−carbon double bonds (between 1.68 and 1.78 Å) 2a…”

Section: Resultsmentioning

confidence: 63%

“…The extrusion of [A−X] + cations as results of the elimination of a one-electron ligand and a two-electron molecule (eqs 3 and 4) is uncommon. Although, it was not rationalized as a reductive process, eq 3 has been previously observed in a few cases for neutral complexes . In 1985, Rubinskaya and co-workers 2b reported that the complexes PdI(CHCHCO 2 R)(PPh 3 ) 2 , on heating in benzene at 75−80 °C, formed PdI{η 2 -CH(PPh 3 )CHCO 2 R}(PPh 3 ) (R = Me, Et).…”

Section: Introductionmentioning

confidence: 97%

Reductive Elimination of [Ph₂CCCHPR₃]BF₄ from the Rhodium(III)−Allenyl Derivatives [Rh(acac){CHCCPh₂}(PR₃)₂]BF₄ (PR₃ = PCy₃, PiPr₃)

et al. 1997

View full text Add to dashboard Cite

The olefinic unit of the complexes Rh(acac)(cyclooctadiene)(PR 3 ) (PR 3 ) PCy 3 (1), PiPr 3 (2)) is displaced by 1,1-diphenyl-2-propyn-1-ol, to afford Rh(acac){η 2 -HCtCC(OH)Ph 2 }(PR 3 ) (PR 3 ) PCy 3 (3), PiPr 3 (4)). At 60 °C, in toluene as solvent, and in the presence of 1 equiv of phosphine, complexes 3 and 4 evolve into Rh(acac)H{CtCC(OH)Ph 2 }(PR 3 ) 2 (PR 3 ) PCy 3 (5), PiPr 3 ( 6)). At -78 °C, the treatment of complex 5 with HBF 4 ‚OEt 2 leads to the allenylphosphonium compound [Rh(acac){η 2 -CH(PCy 3 )dCdCPh 2 }(PCy 3 )]BF 4 (7). The X-ray crystal structure analysis of 7 reveals that the coordination geometry around the rhodium center is almost square-planar with the CH(PCy 3 )dC bond disposed perpendicular to the coordination plane of the rhodium center. The allenylphosphonium ligand of 7 is easily displaced by carbon monoxide, to give Rh(acac)(CO)(PCy 3 ) ( 8) and [Ph 2 CdCdCHPCy 3 ]BF 4 (9). At -78 °C, the protonation of complex 6 leads to the five-coordinate rhodium(III)allenyl derivative [Rh(acac){CHdCdCPh 2 }(PiPr 3 ) 2 ]BF 4 (10), which evolves in solution into [Rh(acac){η 2 -CH(PiPr 3 )dCdCPh 2 }(PiPr 3 )]BF 4 (11). For this isomerization first-order constants k obs were obtained in CD 2 Cl 2 , which give activation parameters of ∆H q) 23 ( 2 kcal mol -1 and ∆S q) 2 ( 2 cal K -1 mol -1 . Similarly to 7, the reaction of complex 11 with carbon monoxide affords Rh(acac)(CO)(PiPr 3 ) ( 12) and [Ph 2 CdCdCHPiPr 3 ]BF 4 (13).

show abstract

“…The migration behaviors between M-R (R= alkyl [38,[55][56][57]59,61,66,68], allyl [48][49] and vinyl [89][90][91][92][93][94][95]) and P-Ar have also been studied for a long time. However, during P-Ar/Pd-Me exchange, there has been no evidence for the participation of the phosphonium intermediate [38].…”

Section: Scheme 30mentioning

confidence: 99%

“…In 1985, Rubinskaya et al discovered an unusual vinyl group migration. Upon heating to 75-80 °C, the Pd(II) complex resulting from vinyl iodide addition (31) was converted to η 2 -olefin complex with bearing a vinyl phosphonium ligand (32) (Scheme 33) [89]. Shortly thereafter, the process was accomplished in catalytic fashion using vinyl triflate instead of vinyl iodide.…”

Section: Scheme 33mentioning

confidence: 99%

Transition metal-mediated metathesis between P–C and M–C bonds: Beyond a side reaction

Lee

Morandi

2019

Coordination Chemistry Reviews

View full text Add to dashboard Cite

Phosphine ligands often play an important role in controlling reactivity and selectivity in transition metal catalyzed reactions. However, one common drawback of the phosphine ligands is the undesired occurrence of an interchange between P bound aryl and M bound aryl or alkyl groups in the catalytic cycle. This results in the formation of undesirable coupling products as well as changes in catalyst structure through the replacement of the phosphine ligand. This review discusses approaches to 2 understand this metathesis reaction between P-C and M-C and its productive application in catalytic reactions.

show abstract

Unusual rearrangement of σ-vinylpalladium complexes into η2-olefin complexes. The structure of (η2-1-triphenylphosphonium-2-carbomethoxyethylene)(triphenylphosphine)iodopalladate

Cited by 34 publications

References 30 publications

Molecular‐Weight‐Enlarged Multiple‐Pincer Ligands: Synthesis and Application in Palladium‐Catalyzed Allylic Substitution Reactions

Molecular‐Weight‐Enlarged Multiple‐Pincer Ligands: Synthesis and Application in Palladium‐Catalyzed Allylic Substitution Reactions

Reductive Elimination of [Ph₂CCCHPR₃]BF₄ from the Rhodium(III)−Allenyl Derivatives [Rh(acac){CHCCPh₂}(PR₃)₂]BF₄ (PR₃ = PCy₃, PiPr₃)

Transition metal-mediated metathesis between P–C and M–C bonds: Beyond a side reaction

Contact Info

Product

Resources

About

Unusual rearrangement of σ-vinylpalladium complexes into η2-olefin complexes. The structure of (η2-1-triphenylphosphonium-2-carbomethoxyethylene)(triphenylphosphine)iodopalladate

Cited by 34 publications

References 30 publications

Molecular‐Weight‐Enlarged Multiple‐Pincer Ligands: Synthesis and Application in Palladium‐Catalyzed Allylic Substitution Reactions

Molecular‐Weight‐Enlarged Multiple‐Pincer Ligands: Synthesis and Application in Palladium‐Catalyzed Allylic Substitution Reactions

Reductive Elimination of [Ph2CCCHPR3]BF4 from the Rhodium(III)−Allenyl Derivatives [Rh(acac){CHCCPh2}(PR3)2]BF4 (PR3 = PCy3, PiPr3)

Transition metal-mediated metathesis between P–C and M–C bonds: Beyond a side reaction

Contact Info

Product

Resources

About

Reductive Elimination of [Ph₂CCCHPR₃]BF₄ from the Rhodium(III)−Allenyl Derivatives [Rh(acac){CHCCPh₂}(PR₃)₂]BF₄ (PR₃ = PCy₃, PiPr₃)