Oxidative Coupling of Acetylenic Alcohols

Stansbury, Harry A.; Proops, William R.

doi:10.1021/jo01048a524

Cited by 33 publications

(6 citation statements)

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“…The formal addition of H 2 Te across 2,4-diyn-1,6-diols 13 leads directly to tellurophenes 12 . Diynediols 13 have been prepared by the oxidative coupling of 1-aryl-1-hydroxy-2-propynes 14 following numerous procedures. − Compounds 14 , in turn, have been prepared by the addition of magnesium acetylides to aryl aldehydes . Several of the reported methods − for coupling alkynols 14 were examined, but diyndiols 13 were isolated in only 10−35% yields.…”

Section: Resultsmentioning

confidence: 99%

Novel 21,23-Ditelluraporphyrins and the First 26,28-Ditellurasapphyrin and 30,33-Ditellurarubyrin

et al. 2010

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5-trimethoxyphenyl meso substituents were prepared by the condensation of 2,5-di [hydroxy-(aryl)methyl]tellurophenes 12 with 2,5-di[2-pyrrolo(aryl)methyl]tellurophenes 15 in the presence of BF 3 -etherate followed by oxidation with p-chloranil. Compounds 15 were prepared from tellurophenes 12 with pyrrole and BF 3 -etherate. Tellurophenes 12 were prepared in 44-72% isolated yield by the addition of 1,6-diarylhexa-2,4-diyn-1,6-diols 13 to the reduction product of Te powder and LiBHEt 3 . No additional Lewis acid was necessary in these reactions. Coupling of 1-aryl-2-propyn-1-ols ( 14) with CuCl, pyridine, and air in MeOH gave diyndiols 13. 26,28-Ditellurasapphyrin 10 was isolated in 0.6% yield from the reaction mixture that produced 9 in 12% isolated yield. The X-ray structure of 10 showed a nearly planar sapphyrin core with the Te atoms of both tellurophene rings pointing to the center of the core. 30,33-Ditellurarubyrin 11 was isolated in 32% yield by the reaction of two equivalents of trifluoroacetic acid with tellurophene dipyrrane 15c. 125 Te NMR spectra were recorded for the compounds of this study.Core-modified porphyrins replace one or two pyrrole N-H groups with O, S, Se, and/or Te atoms. The telluraand ditelluraporphyrins provide the broadest range of unusual structures and chemical reactivity. 23-Telluraporphyrin 1 (Chart 1) has a Te 3 3 3 N distance of 3.13 A ˚, which is less than the sum of van der Waals radii. 1 21-Thia-23-telluraporphyrin 2 has a Te 3 3 3 S distance of 2.65 A ˚,2 which is even more compressed. In 21,23-ditelluraporphyrin 3, the dominant structure both in solution and in the crystalline state is one in which the two Te atoms cannot both occupy the core and one tellurophene is "flipped" with the Te atom pointed away from the porphyrin core (as represented by 3A and 3B in Chart 1). 3 Telluraporphyrins 1 and 2 are easily oxidized, 4 and the close proximity of heteroatoms leads to unusual bonding interactions within the core with Te in the þ4 oxidation state. 5 Telluraporphyrins 1 and 2 are also catalysts for the activation of H 2 O 2 via oxidation of Te(II) to Te(IV). 6 The unusual structure of ditelluraporphyrin 3 gives reduced symmetry relative to other porphyrins, and coremodified porphyrins and spectral features of the ditelluraporphyrin are quite different from those of related structures. The "flipped" tellurophene of 3 exchanges positions with the other tellurophene via a dynamic process, which is observed in temperature-dependent 1 H NMR spectra of 3. 3 At 210 K, the exchange process has slowed to the point that the ring protons of the two different tellurophenes are distinct with a 2 ppm difference in chemical shift. 3 Furthermore, the symmetry is unusual for a porphyrin with four identical meso-substituents with a single mirror plane, as shown in 3A (Chart 1), as the only symmetry element.

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Section: Resultsmentioning

confidence: 99%

Novel 21,23-Ditelluraporphyrins and the First 26,28-Ditellurasapphyrin and 30,33-Ditellurarubyrin

et al. 2010

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“…Zal'kind and Funduiler (17) were the first to observe this coupling reaction as the result of air oxidation in the presence of aqueous cuprous ammonium chloride. Recently, Stansbury and Proops (16) published a method for oxidative coupling in pyridine and methanol. The ammonium salt of V was not oxidized by the first method nor was the free acid or ester oxidized by the second method.…”

Section: Discussionmentioning

confidence: 99%

Preparation and Some Reactions of the Acetylenic Alcohols from Pinonic Acid and Homoterpenylmethyl Ketone.

Lewis¹,

Hedrick²

1964

J. Chem. Eng. Data

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“…Elsewhere, catalysed polymerisation of alkynes has been widely investigated. [16][17][18] In this present investigation, catalytic amounts of various copper salts such as cuprous chloride (CuCl) O), and cupric oxide (CuO) were added to BPEBPA. The thermal-curing behaviour of these materials and pure BPEBPA was investigated using differential scanning calorimetry (DSC).…”

Section: Introductionmentioning

confidence: 99%

High temperature matrix resins based on bispropargyl ethers – part 1

Dhanalakshmi¹,

Alam

Vijayakumar³

2012

High Performance Polymers

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The compound bispropargyl ether of bisphenol-A (BPEBPA) is prepared using phase transfer catalyst. Different copper salts like cuprous chloride (CuCl), cupric chloride dihydrate (CuCl 2 .2H 2 O), copper sulphate pentahydrate (CuSO 4 .5H 2 O), basic copper carbonate (CuCO 3 .Cu(OH) 2 ), cupric acetate monohydrate ((CH 3 COO) 2 Cu.H 2 O), and cupric oxide (CuO) are blended separately with BPEBPA (1%, w/w) and the curing characteristics of these materials are investigated using differential scanning calorimetry (DSC). The presence of copper salt in BPEBPA shifts the curing temperature to a lower temperature region. The materials are thermally cured and the structural characterisation and the thermal properties of these cross-linked materials are investigated using Fourier-transform infrared (FTIR) spectrophotometer and thermogravimetric analyzer (TGA). Of the different copper salts investigated, the presence of copper sulphate pentahydrate in BPEBPA increases the thermal stability of the cured BPEBPA. The thermal degradation products of thermally cured pure BPEBPA and copper salts containing BPEBPA are studied using TG-FTIR. The phenols, substituted phenols, carbon monoxide (CO), carbon dioxide (CO 2 ), and alkenes are major volatiles evolved during the thermal degradation of these materials.

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Oxidative Coupling of Acetylenic Alcohols

Cited by 33 publications

References 0 publications

Novel 21,23-Ditelluraporphyrins and the First 26,28-Ditellurasapphyrin and 30,33-Ditellurarubyrin

Novel 21,23-Ditelluraporphyrins and the First 26,28-Ditellurasapphyrin and 30,33-Ditellurarubyrin

Preparation and Some Reactions of the Acetylenic Alcohols from Pinonic Acid and Homoterpenylmethyl Ketone.

High temperature matrix resins based on bispropargyl ethers – part 1

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