Terminal nickel(ii) amide, alkoxide, and thiolate complexes containing amido diphosphine ligands of the type [N(o-C6H4PR2)2]− (R = Ph, iPr, Cy)

Liang, Lan‐Chang; Chien, Pin‐Shu; Lee, Pei-Ying; Lin, Jiaming; Huang, Yu‐Lun

doi:10.1039/b719894a

Cited by 33 publications

(9 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Single crystals for X-ray diffraction were obtained from a diethyl ether solution stored at −35 °C. The solid-state molecular structure of 10 (Figure ) confirms that the ligand remains bound in a κ 3 -manner, and the nickel–nitrogen bond length of 1.9383(6) Å is comparable to that in other terminal nickel amido complexes (ranging from 1.812(3)–1.932(3) Å), albeit on the longer end which we rationalize as due to steric congestion around the nickel center. ,,− ,,,− The aryl group on the amido ligand is oriented perpendicular to the PPC ligand, and the overall geometry of 10 is distorted square planar geometry with τ 4 = 0.25.…”

Section: Resultsmentioning

confidence: 53%

Ancillary Ligand Modification via Reductive Elimination at Nickel(II)

Zimmerman

Fryzuk

2019

Organometallics

View full text Add to dashboard Cite

The nickel(II) complex [κ3-BnPPC]NiBr (1), stabilized by an orthometalated-phosphine benzyl group and two bulky phosphine donors, results in facile reductive elimination with certain organometallic reagents that can attain the η3-bonding mode. Thus, the reaction of diphenylmethyllithium with 1 produces the Ni(0) derivative [κ2-BnPP(η2-CHPh2)]Ni (4), which forms as a single diastereomer and displays an η2-phenyl moiety. Similarly, reaction of benzylpotassium with 1 results in the analogous nickel(0) complex [κ2-BnPP(η2-CH2Ph)]Ni, albeit less cleanly. Reaction of 1 with allylmagnesium chloride also results in reductive elimination to generate the Ni(0) species [κ2-BnPP(η2-CH2CHCH2)]Ni. In contrast, reaction with trimethylsilylmethyllithium generates the stable Ni(II) derivative, [κ3-BnPPC]Ni(CH2SiMe3), which can only be induced to undergo clean reductive elimination by heating to 80°C in the presence of ethylene. Similarly, the bulky 2,6-di-iso-propyl-phenylamidolithium reacts with 1 to give the stable Ni(II) species [κ3-BnPPC]Ni(NH-2,6-iso-Pr2C6H3), which upon thermolysis in the presence of ethylene results in a mixture of products. It is proposed that facile reductive elimination occurs only for those hydrocarbyl groups that can attain a transient η3-bonding mode that accelerates this process due to the formation of an 18-electron intermediate.

show abstract

Section: Resultsmentioning

confidence: 53%

Ancillary Ligand Modification via Reductive Elimination at Nickel(II)

Zimmerman

Fryzuk

2019

Organometallics

View full text Add to dashboard Cite

show abstract

“…Many of their NMR spectroscopic features (e.g., observation of virtual triplets for OCH 2 groups and a singlet 31 P resonance for the equivalent phosphinite moieties) are similar to those of previously studied analogues and consistent with the proposed structures. [15] The longer Ni À O bonds in 1-OSiMe 3 and 1-OMes are presumably due to the very strong trans influence of nickel-bound central carbon atom of the POC sp3 OP ligand. [11] The Ni centers in 1-OSiMe 3 , 1-OMes, and 1-NPh 2 adopt a square-planar geometry in the solid state (Figure 1), [12] and most of the structural parameters are comparable to those found in 1-Br.…”

mentioning

confidence: 99%

“…[9a] The Ni À N distance of 1.961(3) and the Ni-N-C angles of 120-1228 in 1-NPh 2 are comparable to the corresponding parameters in reported nickel amido complexes, [13] whereas the NiÀO bond is longer in 1-OSiMe 3 (1.873(3) ) and 1-OMes (1.895(1) ) than in two other {Ni À OSiR 3 } complexes (1.820(2) [14a] and 1.831(3) [14b] ) and the closely related {(PNP)Ni-OPh} (1.863 (2) ). [15] The longer Ni À O bonds in 1-OSiMe 3 and 1-OMes are presumably due to the very strong trans influence of nickel-bound central carbon atom of the POC sp3 OP ligand. The relative sizes of the Ni-O-Si/C angles in 1-OSiMe 3 and 1-OMes (1518 vs. 1368) are consistent with a greater degree of O!Si electron delocalization that serves presumably to minimize the d p -p p desta-…”

mentioning

confidence: 99%

On the Stability of a POC_sp3OP‐Type Pincer Ligand in Nickel(II) Complexes

et al. 2014

View full text Add to dashboard Cite

We describe the results of a study on the stabilities of pincer-type nickel complexes relevant to catalytic hydroalkoxylation and hydroamination of olefins, C-C and C-X couplings, and fluorination of alkyl halides. Complexes [(POCsp3 OP)NiX] are stable for X=OSiMe3 , OMes (Mes=1,3,5-Me3 C6 H2), NPh2, and CC-H, whereas the O(tBu) and N(SiMe3)2 derivatives decompose readily. The phenylacetylide derivative transforms gradually into the zero-valent species cis-[{κ(P),κ(C),κ(C')-(iPr2 POCH2 CHCH2 )}Ni{η(2),κ(C),κ(C')-(iPr2 P(O)CCPh)}]. Likewise, attempts to prepare [(POCsp3 OP)NiF] gave instead the zwitterionic trinuclear species [{(η(3) -allyl)Ni}2-{μ,κ(P),κ(O)-(iPr2 PO)4 Ni}]. Characterization of these two complexes provides concrete examples of decomposition processes that can dismantle POCsp3 OP-type pincer ligands by facile C-O bond rupture. These results serve as a cautionary tale for the inherent structural fragility of pincer systems bearing phosphinite donor moieties, and provide guidelines on how to design more robust analogues.

show abstract

“…The reaction of 3 with phenol in the presence of either Et 3 N or potassium hydride gave complex mixtures of products, as evident in the 31 P{ 1 H} NMR spectrum, with the desired phenoxyphosphine representing less than 10% of the mixture. The use of isolated KOPh was however more fruitful, resulting in a 31 P{ 1 H} NMR spectrum of the crude reaction mixture containing one major product at δ P = 127.1 ( 2 J WP 74.0 Hz), for which both the chemical shift (cf. P(OPh)Ph 2 δ P 111.0) and the magnitude of the coupling constant are consistent with the desired product [W{CP(OPh)Ph}(CO) 2 (Tp*)] ( 8 ) (Scheme ).…”

Section: Resultsmentioning

confidence: 99%

“…Data for X-ray crystallography were collected with a Nonius Kappa CCD diffractometer. The compounds [W(CBr)(CO) 2 (Tp*)], KOPh, and LiCCPh were prepared according to published procedures. All other reagents were used as obtained from commercial sources.…”

Section: Methodsmentioning

confidence: 99%

Chlorophosphino Carbyne Complexes of Tungsten

Colebatch

Hill

2016

Organometallics

View full text Add to dashboard Cite

A range of chlorophosphinocarbyne complexes [W(CPClR)(CO) 2 (Tp*)] (R = Cl, Cy, Ph; Tp* = hydrotris-(3,5-dimethylpyrazol-1-yl)borate) has been prepared by reaction of chlorophosphines with the lithiocarbyne complex [W{ CLi(THF) n }(CO) 2 (Tp*)]. These complexes undergo nucleophilic substitution of chloride to enable the preparation of phosphinocarbynes bearing alkyl, aryl, alkynyl, aryloxy, and secondary phosphino substituents [W(CPRR′)(CO) 2 (Tp*)] (R = Ph, R′ = Me, Ph, CCPh, OPh, H; R = Cy, R′ = H). ■ INTRODUCTIONCarbynes L n MCR, as one of the simplest carbon-based ligands, and phosphines, as ubiquitous (spectator and noninnocent) ligands, both represent in their own way fundamental groups in organometallic chemistry. Despite dating back to Fischer's seminal report in 1973, 1 the appearance of carbyne complexes in the literature remains somewhat sporadic. A notable exception to this involves carbyne complexes serving as catalysts for alkyne metathesis, which continues to receive considerable attention. 2−8 Carbyne complexes bearing heteroatom carbyne substituents have been less studied, and in part this reflects limitations in synthetic methodologies that are typically distinct from classical Fischer or Schrock protocols. 9−16 We have enjoyed some success employing the "M-(CO) 2 (Tp*)" fragments (M = Mo, W; Tp* = 3,5-hydrotris-(dimethylpyrazolyl)borate)) for the construction of comparatively elaborate carbyne complexes, in particular those that bear heteroatomic carbyne subsitutents. 17−29 The combination of the bulky Tp* ligand (Tolman cone angle = 224°), 30 which affords kinetic stabilization, and the π-acidic CO coligands, which render the metal center relatively inert, allows modifications at the carbyne ligand to proceed, in many cases, without disruption of the MC linkage or M-(CO) 2 (Tp*) coordination sphere. In contrast to carbyne chemistry, phosphorus chemistry is very mature. Chlorophosphines are the quintessential building blocks for a myriad of phosphorus species due to the high reactivity of the P−Cl linkage and subsequent ease of nucleophilic substitution at this position.Combining these two principles we have considered the marriage of conventional organophosphorus chemistry with that of carbyne complexes. We have previously demonstrated that tertiary phosphinocarbyne complexes [M(CPPh 2 )-(CO) 2 (Tp*)] (M = W 2a, Mo 2b)) 21,29 and phosphonito carbynes [Mo{CP(O)(OEt) 2 }(CO) 2 (Tp*)] 21 are readily accessible from the bromocarbyne precursor [M(CBr)-(CO) 2 (Tp*)] (M = W 1a, Mo 1b) via lithium/halogen exchange with n BuLi and nucleophilic substitution of PClPh 2 or alternatively via palladium-catalyzed phosphination using PH-(O)(OEt) 2 , respectively. These complexes possess relatively inert phosphorus centers, undergoing conventional "phosphinetype" reactions with electrophiles, oxidants, and metal centers.In search of more versatile precursors, it has been found that the palladium-mediated protocol is also effective for the preparation of secondary phosphinocarbynes [W(CPHR)-(CO) 2 (Tp...

show abstract

Terminal nickel(ii) amide, alkoxide, and thiolate complexes containing amido diphosphine ligands of the type [N(o-C6H4PR2)2]− (R = Ph, iPr, Cy)

Cited by 33 publications

References 41 publications

Ancillary Ligand Modification via Reductive Elimination at Nickel(II)

Ancillary Ligand Modification via Reductive Elimination at Nickel(II)

On the Stability of a POC_sp3OP‐Type Pincer Ligand in Nickel(II) Complexes

Chlorophosphino Carbyne Complexes of Tungsten

Contact Info

Product

Resources

About

Terminal nickel(ii) amide, alkoxide, and thiolate complexes containing amido diphosphine ligands of the type [N(o-C6H4PR2)2]− (R = Ph, iPr, Cy)

Cited by 33 publications

References 41 publications

Ancillary Ligand Modification via Reductive Elimination at Nickel(II)

Ancillary Ligand Modification via Reductive Elimination at Nickel(II)

On the Stability of a POCsp3OP‐Type Pincer Ligand in Nickel(II) Complexes

Chlorophosphino Carbyne Complexes of Tungsten

Contact Info

Product

Resources

About

On the Stability of a POC_sp3OP‐Type Pincer Ligand in Nickel(II) Complexes