Rhodium(I)-catalysed dimerisation of terminal acetylenes at ambient temperature and pressure

Carlton, Laurence; Read, G.

doi:10.1039/p19780001631

Cited by 42 publications

(11 citation statements)

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“…13 C NMR δ 14.21, 14.25, 19.68, 22.74, 28.71, 29.02, 30.18, 31.53, 31.84, 94.59, 109.42, 142.82. 1 H NMR and IR spectral data were in good agreement with those described in the literature …”

Section: Methodssupporting

confidence: 88%

Insertion of 1-Chloro-1-lithioalkenes into Organozirconocenes. A Versatile Synthesis of Stereodefined Unsaturated Systems

Kasatkin

Whitby

1999

J. Am. Chem. Soc.

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Hydrozirconation of alkenes and alkynes, followed by insertion of 1-halo-1-lithio-1-alkenes, generated in situ by lithium tetramethylpiperidide deprotonation of vinyl halides, affords vinylzirconocene species which may be further elaborated. The method provides easy access to many structures including terminal (3E)- and (3Z)-1,3-dienes and (3E,5E)- and (3Z,5E)-1,3,5-trienes, and internal (E,Z)-dienes, (E,Z,E)-trienes, and (1E,3Z)-1,3-dien-5-ynes. Insertion of 2-monosubstituted 1-halo-1-lithio-1-alkenes occurs with clean inversion of configuration of the sp2-carbenoid carbon. Carbenoids derived by deprotonation of 2,2-disubstituted 1-halo-1-alkenes gave poor stereocontrol probably due to isomerization before insertion into the organozirconium species. Insertion of vinyl carbenoids into alkynylzirconocenes affords terminal (3E)- or (3Z)-1,3-dien-5-ynes, internal (1E,3Z)-1,3-dien-5-ynes, and (Z)-3-en-1,5-diynes.

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Section: Methodssupporting

confidence: 88%

Insertion of 1-Chloro-1-lithioalkenes into Organozirconocenes. A Versatile Synthesis of Stereodefined Unsaturated Systems

Kasatkin

Whitby

1999

J. Am. Chem. Soc.

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“…Another possible pathway for the dimerization is an intermolecular, nonoxidative coupling between two ethynyl groups, promoted by rhodium complex VI , generating in this case enyne 11 (Scheme ). Dimerizations of this type involving terminal alkynes have been reported in the presence of Wilkinson's catalyst 43–45. Single‐bridged enyne 11 may well participate in further reactions yielding products similar to those described for the oxidative route [double‐bridge formation ( 12 ), oligomerization, and polymerization].…”

Section: Resultsmentioning

confidence: 95%

“…alkynes have been reported in the presence of Wilkinson's catalyst. [43][44][45] Single-bridged enyne 11 may well participate in further reactions yielding products similar to those described for the oxidative route [double-bridge formation (12), oligomerization, and polymerization].…”

Section: Polymerization Of Calixarenementioning

confidence: 97%

Synthesis and Rh(I)‐catalyzed polymerization of 1,3‐diphenylyne–calix[4]arene compounds: Novel conjugated, calixarene‐based polymers

Costa

Prata

2006

J. Polym. Sci. A Polym. Chem.

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The synthesis of two 1,3‐bis(4‐ethynylbenzyloxy)calix[4]arenes, 5,11,17,23‐tetrakis(1,1‐dimethylethyl)‐25,27‐bis(4‐ethynylbenzyloxy)‐26,28‐dihydroxycalix[4]arene (1) and 25,27‐bis(4‐ethynylbenzyloxy)‐26,28‐dihydroxycalix[4]arene (2), was accomplished through Sonogashira coupling of appropriate calixarene derivatives. Methods for the polymerization of these bifunctional building blocks with Rh(I) as a catalyst, leading ultimately to conjugated polymers having calix[4]arene units incorporated into the main chain, were explored. Calixarenes 1 and 2 were efficiently polymerized with rhodium‐based initiators and afforded the conjugated polymers poly{5,11,17,23‐tetrakis(1,1‐dimethylethyl)‐25,27‐bis(4‐ethynylbenzyloxy)‐26,28‐dihydroxycalix[4]arene} (poly 1) and poly{25,27‐bis(4‐ethynylbenzyloxy)‐26,28‐dihydroxycalix[4]arene}. Depending on the conditions, high conversions and good yields were obtained. The effects of adding cocatalysts (NHEt2 and/or PPh3) were studied in connection with the number‐average molecular weight and the molecular weight distribution of the resultant polymer (poly 1) and tentatively correlated with the formation of low‐molecular‐weight materials. A catalytic system containing triphenylphosphine as the sole additive ([Rh(nbd)Cl]2; [Rh]/[PPh3] = 0.5) proved to be the best for the polymerization of p‐tert‐butylcalixarene compound 1. Linear polymers having high number‐average molecular weights (up to 1.1 × 105 g mol−1) with low polydispersities were produced under these conditions. For debutylated homologue 2, its polymerization was best carried out in the absence of any added cocatalyst. A cyclopolymerization route, comprising the intramolecular ring closing of the calix[4]arene pendant ethynyl groups followed by an intermolecular propagation step, is advanced to explain the results. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 7054–7070, 2006

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“…Loss of the NO ligand enabling formation of [(η-Cp)Ni] 2 (PhC᎐ ᎐ ᎐ CH) occurs only with difficulty. Indeed, it has been found that nitrosyl exchange with 15 NO did not occur for (η-Cp)Ni(NO) in 10 d at 120 ЊC. 53 The complex (η-Cp)Ni(GeBr 3 )(CO) gave very similar results (Table 2, entry 4) to those for (η-Cp)Ni(NO), suggesting that although the CO ligand is readily lost (as shown by the initially green solution turning orange-red after only 1 min at 115 ЊC), the presence of the electron-withdrawing GeBr 3 substituent 5 hinders subsequent reactions with phenylacetylene.…”

Section: Solvent-free Polymerization In the Presence Of Other (Cyclop...mentioning

confidence: 99%

Solvent-free oligomerization of phenylacetylene catalyzed by (cyclopentadienyl)nickel complexes

Douglas

2000

J. Chem. Soc., Dalton Trans.

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The solvent-free reaction of phenylacetylene at 115 ЊC in the presence of nickelocene,n P)I, or (Ph 3 P) 2 Ni(CO) 2 gives rise to a mixture of cyclotrimers, linear oligomers and poly(phenylacetylene), no reaction being observed in the case of internal acetylenes. Cyclotrimer formation is favoured by the presence of (a) added phosphine (2 equiv.), or (b) (cyclopentadienyl)nickel catalysts bearing a chloro substituent at Ni. A reduction in reaction temperature results in lower conversion but favours linear oligomer and polymer formation. The extent of reaction is greatly reduced in the case of (a) nickelocene in the presence of 2 equiv. PBu 3 n , (b) (η-Cp)Ni(GeBr 3 )(CO), or (c) (η-Cp)Ni(NO). The main effect of the presence of solvent, regardless of whether it is potentially coordinating (toluene) or not (n-octane), is to suppress almost completely reactions catalyzed by nickelocene.

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Rhodium(I)-catalysed dimerisation of terminal acetylenes at ambient temperature and pressure

Abstract: H-7).1955.

Cited by 42 publications

References 0 publications

Insertion of 1-Chloro-1-lithioalkenes into Organozirconocenes. A Versatile Synthesis of Stereodefined Unsaturated Systems

Insertion of 1-Chloro-1-lithioalkenes into Organozirconocenes. A Versatile Synthesis of Stereodefined Unsaturated Systems

Synthesis and Rh(I)‐catalyzed polymerization of 1,3‐diphenylyne–calix[4]arene compounds: Novel conjugated, calixarene‐based polymers

Solvent-free oligomerization of phenylacetylene catalyzed by (cyclopentadienyl)nickel complexes

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