Photoinduced carbonylation of the carbyne ligand in (.eta.-C5H5)(CO)2W.tplbond.CTol

Sheridan, John B.; Pourreau, Daniel B.; Geoffroy, Gregory L.; Rheingold, Arnold L.

doi:10.1021/om00092a009

Cited by 37 publications

(9 citation statements)

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“…However, the calculated carbyne‐CO coupling from 1 resulted in the endergonic formation of η 1 ‐ketenyl complex 3 with C1=C6 and C6=O double bonds (1.343 and 1.167 Å, respectively), instead of the expected formation of a metallacyclopropenone. Similar formation of η 1 ‐ketenyl complexes via carbyne‐CO coupling has been described previously [16a] . This transformation proceeds via TS 1 – 3 with an activation barrier of +33.8 kcal/mol, which is much higher than that of the above [2+2] cycloaddition.…”

Section: Resultssupporting

confidence: 77%

Computational Mechanistic Study of Fused Phenol Formations from 1,6‐Heptadiyne Involving Carbyne Complexes

Yamamoto

2021

ChemCatChem

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The reaction of a tungsten carbyne complex, MeC≡WBr(CO)4, with 1,6‐heptadiyne was investigated using density functional theory (DFT) calculations. It was suggested that the plausible mechanism involves [2+2] cycloaddition of the carbyne with the diyne, subsequent insertion of CO and alkyne into a metallacyclobutadiene intermediate, and a final reductive elimination step from a metallacycloheptatrienone intermediate to produce a η5‐cyclohexadienyl complex. A related Ru‐catalyzed reaction of 1,6‐heptadiyne involving a hydroxycarbyne complex was investigated to propose a possible pathway starting from a bis(hydroxycarbyne) complex, (HOC≡)2Ru(CO)2. It was found that the biscarbyne complex undergoes carbyne‐carbyne coupling to generate a stable metallacyclopropene intermediate, which reacts with 1,6‐heptadiyne through two different pathways to produce the final η6‐arene complex. Moreover, a non‐carbyne pathway was also investigated to propose an alternative mechanism.

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Section: Resultssupporting

confidence: 77%

Computational Mechanistic Study of Fused Phenol Formations from 1,6‐Heptadiyne Involving Carbyne Complexes

Yamamoto

2021

ChemCatChem

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“…[20] Subsequently, Geoffroy demonstrated that such processes could be photochemically induced. [21] Ketenyl formation through alkylidyne/carbonyl coupling has since been reviewed, [22] whilst the synthetic utility of ketenyl complexes has been amply demonstrated by Kreiβl. [23] The clarification of the processes involved in the reactions of 2 with isocyanides called for selective synthesis of the products since the reactions themselves were not synthetically useful in that the mixtures obtained required cryostatic chromatography (Ϫ40°C) and the purified products were unstable at room temperature.…”

Section: Resultsmentioning

confidence: 99%

Dihydrobis(pyrazolyl)borate Alkylidyne Complexes of Tungsten

et al. 2004

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[W(≡CR)Br(CO)2(NC5H4Me‐4)2] (R = C6H3Me2‐2,6 1a, C6H2Me3‐2,4,6 1b) react with K[H2B(pz)2] (pz = pyrazol‐1yl) to provide two interconverting isomers of [W(≡CR)(CO)2(NC5H4Me‐4){H2B(pz)2}] (2), one isomer having been structurally characterised for R = C6H3Me2‐2,6 (2a). The reactions of [W(≡CR)Br(CO)2(CNR′)2] (5: R′ = C6H3Me2‐2,6, CNMe3) with K[H2B(pz)2] or of [W(≡CR)Br(CO)2(NC5H4Me‐4){H2B(pz)2}] (2) with isocyanides are more complex due to the facile formation of unstable ketenyl derivatives. In the absence of light, the reaction of [W(≡CR)Br(CO)2(CNR′)2] (5) with K[H2B(pz)2] provides [W(≡CR)(CO)2(CNR′){H2B(pz)2}] (3) in moderate yield, similar yields were obtained from [W(≡CR)(CO)2(NC5H4Me‐4){H2B(pz)2}] (2) and CNR′. Under mild photolytic conditions both combinations provide primarily the thermally unstable ketenyl complex [W(η2‐OCCR)(CO)(CNR′)2{H2B(pz)2}] (4). The picoline ligand in [W(≡CR)Br(CO)2(NC5H4Me‐4){H2B(pz)2}] (2) is readily replaced by PMe2Ph to provide [W(≡CR)(CO)2(PMe2Ph){H2B(pz)2}] (structurally characterised for R = C6H3Me2‐2,6 6a). The reaction of either [W(≡CR)(CO)2(PMe2Ph){H2B(pz)2}] (6) or [W(≡CR)(CO)2(NC5H4Me‐4){H2B(pz)2}] (R = C6H2Me3‐2,4,6 2b) with excess PMe2Ph provides [W(≡CR)(CO)(PMe2Ph)2{H2B(pz)2}] (7). This complex is also obtained from K[H2B(pz)2] and [W(≡CR)Br(CO)(PMe2Ph)3] (8), the latter arising from the reaction of [W(≡CR)Br(CO)2(NC5H4Me‐4)2] (1b) with PMe2Ph. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

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“…Complex 12 was prepared by a similar procedure, as shown in Schemes 1 and 2. The heteronuclear metal complexes 13-28 were prepared by reaction of the respective isocyano-terminated alkylidyne tungsten complexes 7-12 with the metal complex reagents Cr(CO) 5 (THF) (13), ReCl(CO) 3 (THF) 2 (14, 19,22), ReBr(CO) 3 (THF) 2 (15), PdCl 2 (16), PdI 2 (17,20,23,25,27), and PtI 2 (18, 21,24,26,28) in THF or dichloromethane solution (see Scheme 3). The compounds were recrystallized from dichloromethane and hexane.…”

Section: Synthesis Of the Metal Complexesmentioning

confidence: 99%

“…Other experiments suggest that in carbonylmetal alkylidyne systems the initial excited state rearranges into a metal ketenyl species B by forming a bond between the alkylidyne ligand and a carbonyl ligand. Supporting evidence for structure B derives from the observation that the excited states of alkylidyne carbonyltungsten complexes can be trapped as ketenyl derivatives by nucleophiles [26] or as oxyacetylene species by electrophiles [27]. In B the excited electron would most likely be associated with the newly formed carbon-carbon linkage.…”

Section: Emission Properties Of the Metal Complexesmentioning

confidence: 99%

Electronic communication between tungsten alkylidyne and metal isocyanide complex fragments across phenyleneethynylene bridges

Yam

Cheung

et al. 2006

Journal of Organometallic Chemistry

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Photoinduced carbonylation of the carbyne ligand in (.eta.-C5H5)(CO)2W.tplbond.CTol

Cited by 37 publications

References 0 publications

Computational Mechanistic Study of Fused Phenol Formations from 1,6‐Heptadiyne Involving Carbyne Complexes

Computational Mechanistic Study of Fused Phenol Formations from 1,6‐Heptadiyne Involving Carbyne Complexes

Dihydrobis(pyrazolyl)borate Alkylidyne Complexes of Tungsten

Electronic communication between tungsten alkylidyne and metal isocyanide complex fragments across phenyleneethynylene bridges

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