Total synthesis of polyyne natural products

Gung, Benjamin W.

doi:10.1016/j.crci.2008.08.014

Cited by 47 publications

(14 citation statements)

References 89 publications

(137 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[7][8][9][10][11][12][13][14] Its natural existence has been proposed in, for example, meteorites, 15,16 interstellar dust, 17 and shock-compressed graphite, 18 as well as terrestrial plant, fungal, and marine sources (in the case of polyynes). [19][20][21] Furthermore, carbyne has been reportedly formed in the laboratory by a variety of processes, e.g., by solution-phase synthesis, 12,22,23 laser irradiation of graphite, 24 or gas-phase deposition methods. 25 Whether naturally occurring or produced in a laboratory, carbyne remains rather poorly characterized as a material, and the specific properties of carbyne are thus often difficult to define (at least in the opinion of the authors of this review).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and properties of long [n]cumulenes (n≥ 5)

2014

View full text Add to dashboard Cite

Molecules composed of a contiguous sequence of double bonds, the [n]cumulenes, share structural similarities to both of their conjugated relatives, the polyenes and polyynes. The synthesis and properties of [n]cumulenes are, however, quite different from those of either polyenes or polyynes. At an infinite length, [n]cumulenes would provide one structural form of the hypothetical sp-hybridized carbon allotrope carbyne, while shorter derivatives offer model compounds to help to predict the properties of carbyne. Finally, derivatization of the π-electron framework of [n]cumulenes provides a number of different synthetic transformations, with cycloaddition reactions being the most common. In this review, both historical and recent synthetic achievements toward long [n]cumulenes (n ≥ 5) are discussed. This is followed by a description of our current understanding of the physical and electronic structure of [n]cumulenes based on UV/vis spectroscopy and X-ray crystallography. Finally, the reactivity of long [n]cumulenes is described.

show abstract

Section: Introductionmentioning

confidence: 99%

Synthesis and properties of long [n]cumulenes (n≥ 5)

2014

View full text Add to dashboard Cite

show abstract

“…At last, the screened antioxidants were regarded to be the identified polyynes, phenylpropanoids and their derivatives, which were ferulic acid, caffeic acid, homovanillyl alcohol 4‐ O ‐β‐ d ‐glucopyranoside, 3,4‐dihydroxyphenethyl alcohol 4‐ O ‐β‐ d ‐glucopyranoside, 3,5‐dimethoxycinnamyl alcohol 4‐ O ‐β‐ d ‐glucopyranoside, scopoletin, esculetin, and (+)‐isolariciresinol‐9′‐ O ‐β‐ d ‐glucopyranoside (Table ). Polyynes, also known as polyacetylenes, have been discovered in many dietary and herbal plants, which were reported to have antioxidant effects . As shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…At last, the screened antioxidants were regarded to be the identified polyynes, phenylpropanoids and their derivatives, which were ferulic acid, caffeic acid, (Table 4). Polyynes, also known as polyacetylenes, have been discovered in many dietary and herbal plants, which were reported to have antioxidant effects [27][28][29]. As shown in Fig.…”

Section: Off-line 2d Hplc-dad-tof-ms Analysis and Identificationmentioning

confidence: 99%

Screening and identifying antioxidants from Oplopanax elatus using 2,2ʹ‐diphenyl‐1‐picrylhydrazyl with off‐line two‐dimensional HPLC coupled with diode array detection and tandem time‐of‐flight mass spectrometry

Shao

Nie

Chen

et al. 2016

J of Separation Science

View full text Add to dashboard Cite

The root of Oplopanax elatus (Nakai) Nakai has a well-known history of use for the treatment of diseases such as neurasthenia, cardiovascular disorders, and cancer by the native people in northeast China. It is important to screen and identify the bioactive molecules from its root rapidly. Hereby, an off-line two-dimensional high performance liquid chromatography coupled with diode array detection and tandem time-of-flight mass spectrometry together with 2,2'-diphenyl-1-picrylhydrazyl was established to screen antioxidants from the root of O. elatus. A Waters cyanogen column (150 × 3.9 mm, id, 4 μm) was used for the first dimensional liquid chromatography, while a Hypersil BDS-C18 column (250 × 4.6 mm, id, 5 μm) was installed for the second dimension liquid chromatographic analysis. Twenty-eight compounds had been tentatively identified from the methanol extract of the air-dried root of O. elatus including six polyynes and eight phenolic derivatives were screened with antioxidant activity. The developed method could be expedient for screening and identifying antioxidants from O. elatus.

show abstract

“…13 C-labeling experiments provide clear evidence that these reactions proceed in a similar fashion to that established for conventional metal-catalyzed alkyne metathesis, which involves cleavage and formation of carbon-carbon triple bonds via metallacyclobutadiene intermediates. [30,31] Received: March 16, 2012 Published online: May 23, 2012 . Therefore, we feel that this new method will be a useful and versatile addition to the methods available in preparative acetylenic chemistry, [29] for example in natural product and polymer synthesis.…”

mentioning

confidence: 99%

“…Therefore, we feel that this new method will be a useful and versatile addition to the methods available in preparative acetylenic chemistry, [29] for example in natural product and polymer synthesis. [30,31] Received: March 16, 2012 Published online: May 23, 2012 . Keywords: alkyne metathesis · alkynes · cyclophanes · diynes · tungsten…”

mentioning

confidence: 99%

Catalytic Metathesis of Conjugated Diynes

et al. 2012

View full text Add to dashboard Cite

Alkyne metathesis has recently witnessed a significant growth in the number of homogeneous catalysts that are able to efficiently promote the formation and cleavage of carboncarbon triple bonds. [1, 2] All well-defined catalyst systems reported to date can be regarded as variants of Schrock-type molybdenum(VI) or tungsten(VI) alkylidyne complexes [3] in which the metal-alkylidyne moiety, MCÀR, is supported by alkoxide, [4] arlyoxide, [5] amido, [6] imidazolin-2-iminato, [7] phosphoraneiminato, [8] or silanolate ligands. [9,10] With a few exceptions, [11] alkyne metathesis usually requires the presence of internal alkynes, such as RCCMe (R = alkyl or aryl), affording the symmetric alkynes RCCR and MeCCMe. To drive these equilibrium reactions to completion, the latter, 2butyne (b.p. = 27 8C), can be continuously removed from the reaction mixtures under vacuum-driven conditions or, as recently shown by Fürstner and co-workers, advantageously by addition of molecular sieves (5 M.S.) to adsorb 2butyne. [9,12] For our part, the molecular-sieve-promoted method was also clearly superior when alkyne homocoupling and ring-closing alkyne metathesis (RCAM) reactions were studied in the presence of catalytic amounts of the tri(tertbutoxy)silanolate-supported tungsten benzylidyne complex 1 (Scheme 1). [10]

show abstract

Total synthesis of polyyne natural products

Cited by 47 publications

References 89 publications

Synthesis and properties of long [n]cumulenes (n≥ 5)

Synthesis and properties of long [n]cumulenes (n≥ 5)

Screening and identifying antioxidants from Oplopanax elatus using 2,2ʹ‐diphenyl‐1‐picrylhydrazyl with off‐line two‐dimensional HPLC coupled with diode array detection and tandem time‐of‐flight mass spectrometry

Catalytic Metathesis of Conjugated Diynes

Contact Info

Product

Resources

About