Preparation of Alkynes

Sowa, John R.; Lamby, Edward John; Calamai, Elisa; Benko, D. A.; GORDINIER, A.

doi:10.1080/00304947509355133

Cited by 14 publications

(2 citation statements)

References 2 publications

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“…We have observed that 1 is soluble in THF and pyridine, unlike most other copper® acetylides.ud Soluble in situ generated copper® acetylides have been reported using N-ethylpiperidine as base. The yields of coupled products were low, however.118 1,1 -Diethoxy-2 -propyne15 (2) was dissolved in dry tetrahydrofuran (THF) and deprotonated with n-butyllithium.…”

Section: Allinger7bmentioning

confidence: 99%

A synthesis of terminal arylacetylenes - an in situ generated copper(I) acetylide

Kiely¹,

Boudjouk²,

NELSON³

1977

J. Org. Chem.

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Section: Allinger7bmentioning

confidence: 99%

A synthesis of terminal arylacetylenes - an in situ generated copper(I) acetylide

Kiely¹,

Boudjouk²,

NELSON³

1977

J. Org. Chem.

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“…[(o-Trimethylsilyl)phenyl]acetylene, 19 tert-butylacetylene, 20 • 21 and l-chloro-l-octyne 22 were synthesized according to the literature methods and purified by distillation. Norbornene was distilled from CaH 2 and stored as toluene solution.…”

Section: Methodsmentioning

confidence: 99%

Metathesis Polymerization of Substituted Acetylenes and Norbornene by M(CO)6-Ph2CCl2-hν (M=Mo, W) Catalysts

Misumi

Tamura

Nakako

et al. 1998

Polym J

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ABSTRACT:The M(CO)6-Ph2 CCl2-hv (M = W, Mo) systems worked as effective catalysts in the metathesis polymerization of substituted acetylenes and norbornene. Thus, W(CO) 6-Ph 2 CC1 2 -hv polymerized phenylacetylene in toluene at 30''C for 24 h to provide a polymer with M w 30000 in 70% yield, and polymerized norbornene at 60°C to give a polymer with M., 26000 quantitatively. Ph 2 CCl2 and ultraviolet (UV) irradiation were essential for the catalytic activity. However, Ph 2 CC1 2 was sufficient in catalytic amounts unlike the M(CO) 6---CC14-hv systems which require CC14 as solvent. A maximum was seen in catalytic activity at [Ph2CCl2]/[M]=0.5-2. The molecular weight of the poly(phenylacetylene) was higher than those for MCl"-based catalysts.KEY WORDS Metathesis Polymerization / Substituted Acetylene / Norbornene / Diphenyldichloromethane / Ultraviolet Irradiation / It is well known that ring-opening metathesis polymerization of cycloolefins is effected by various transition metal catalysts. 1 -3 Such catalysts include transition metal chloride-organometallic cocatalyst systems, 1 -3 metallacyclobutanes, 4 -6 Schrock-type metal carbenes, 7 ruthenium carbenes developed by Grubbs et al. 8 Groups 5 and 6 transition metal chloride-based catalysts,9 Schrock-type metal carbenes, 10 • 11 etc. are effective in metathesis polymerization of substituted acetylenes as well. Polymerization of phenylacetylene readily proceeds in the presence of metal chloride-based catalysts, but the molecular weight of the formed polymer is around 5000 at highest probably due to the Lewis acidity of the catalysts. 9 Group 6 transition metal hexacarbonyl-based catalysts, M(CO) 6 -CClchv (M = W, Mo), induce metathesis polymerization of both cycloolefins 12 · 13 and substituted acetylenes. 14 • 15 The Lewis acidity of these catalysts is lower than those of metal chlorides, and consequently the molecular weight of the poly(phenylacetylene) produced by the W(COkbased catalyst reaches almost a hundred thousand. A requirement for the M(C0) 6 -based catalysts is that CC1 4 must be used as solvent; otherwise sufficient catalytic activity is not attained. It is assumed that a metal carbene, which serves as active species, is generated by CO elimination from M(CO) 6 by ultraviolet (UV) irradiation and subsequent reactions of M(CO) 5 with CC1 4 , and so forth. 16 Further, generation of tungsten diphenylcarbene as an intermediate in the W(CO) 6 -Ph 2 CC1 2 -hv system was suggested on the basis of a finding that the presence of 2-ethoxynorbornene in this system leads to the formation of a diphenylcarbene adduct. 17 Taking this into account, we examined Ph 2 CCl 2 in place of CC14 in the W(CO) 6 -CC1 4 -hv system to find that the W(CO) 6 -Ph2CC12-hv system polymerizes phenylacetylene. 18 In the present study, we investigated the polymerization of substituted acetylenes and norbornene by the M(CO)6-Ph2CC12-hv (M = W, Mo) systems in detail to clarify the effectiveness of Ph 2 CC1 2 as second catalyst component 1 To whom all correspondence should be addressed. a...

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