In situ alcohol oxidation-Wittig reactions using N-methoxy-N-methyl-2-(triphenylphosphoranylidine)acetamide: application to the synthesis of a novel analogue of 5-oxo-eicosatetraenoic acid

Blackburn, Leonie; Kanno, Hisashi; Taylor, Richard J.K.

doi:10.1016/s0040-4039(02)02498-x

Cited by 31 publications

(10 citation statements)

References 13 publications

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“…Although, most of the above TOP−Wittig reactions have employed ester- and ketone-stabilized Wittig reagents, other stabilized ylides have also been used to prepare unsaturated nitriles and fluorenes (Scheme ) 8 and Weinreb amide adducts (Scheme ) …”

Section: Manganese Dioxide Top−wittig and Related Reactionsmentioning

confidence: 99%

“…Even more surprisingly, in the presence of stabilized phosphorane reagents, MnO 2 has been shown to be an efficient oxidant of unactivated alcohols to afford unsaturated esters in good yield (Scheme ). , These results seem to contradict the well-known dictum that activated MnO 2 will oxidize only allylic/propargylic/benzylic alcohols, giving disappointing yields with primary aliphatic alcohols. ,, The activity of the MnO 2 seems to be enhanced by the presence of phosphorus reagents/byproducts because only 12% of decanal is isolated when decanol is treated with MnO 2 in toluene at reflux for 24 h (although another explanation is that the Wittig reagent removes small equilibrium quantities of aldehyde)…”

Section: Manganese Dioxide Top−wittig and Related Reactionsmentioning

confidence: 99%

See 1 more Smart Citation

Tandem Oxidation Processes Using Manganese Dioxide: Discovery, Applications, and Current Studies

et al. 2005

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"One-pot" processes in which alcohol oxidations are combined with further elaboration of the carbonyl intermediate are reviewed. Sequential processes are briefly discussed, but most attention is centered on tandem processes; that is, oxidations carried out in the presence of a nucleophilic trapping agent, rather than those in which the trapping agent is added after the oxidation is complete. As part of this Account, a comprehensive review of the discovery of tandem oxidation processes (TOP) will be given together with applications in alkene-forming reactions, cyclopropanations, and imine, oxime, amine, and heterocycle formation.

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Section: Manganese Dioxide Top−wittig and Related Reactionsmentioning

confidence: 99%

Section: Manganese Dioxide Top−wittig and Related Reactionsmentioning

confidence: 99%

Tandem Oxidation Processes Using Manganese Dioxide: Discovery, Applications, and Current Studies

et al. 2005

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“…One-pot oxidation-Wittig olefination reactions are also quite common [40,, especially when the carbonyl component is labile [89,97]. Often, the oxidant of choice is MnO 2 [40,[43][44][45][46][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97], although a number of reactions are known where transformations were carried with air oxygen using metals and metal oxides as catalysts [72][73][74][75][76][77][78]. As many Wittig-and HWE reactions tolerate metal catalysts, this allows the running of Wittig/HWE reactions in combination with metal catalyzed cross coupling reactions and olefinations such as Heck [114][115][116][117][118][119][120][121][122][123], Suzuki [111]…”

Section: Resultsmentioning

confidence: 99%

Tandem-, Domino- and One-Pot Reactions Involving Wittig- and Horner-Wadsworth-Emmons Olefination

Merza¹,

Taha²,

Thiemann³

2018

Alkenes

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The Wittig olefination utilizing phosphoranes and the related Horner-WadsworthEmmons (HWE) reaction using phosphonates transform aldehydes and ketones into substituted alkenes. Because of the versatility of the reactions and the compatibility of many functional groups towards the transformations, both Wittig olefination and HWE reactions are a mainstay in the arsenal of organic synthesis. Here, an overview is given on Wittig-and Horner-Wadsworth-Emmons (HWE) reactions run in combination with other transformations in one-pot procedures. The focus lies on one-pot oxidation Wittig/HWE protocols, Wittig/HWE olefinations run in concert with metal catalyzed cross-coupling reactions, Domino Wittig/HWE-cycloaddition and Wittig-Michael transformations.

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“…Taylor's work has shown that in situ MnO 2 oxidation/Wittig reaction 83 is not restricted to allylic alcohols as substrates, and has been extended to the one-pot oxidative preparation of Weinreb amide derivatives (Scheme 13). 84…”

Section: Scheme 12mentioning

confidence: 99%

3 Synthetic methods : Part (ii) Oxidation and reduction methods

Armstrong

Knight

2004

Annu. Rep. Prog. Chem., Sect. B

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As in last year's account, this Report will highlight work on some of the most commonly used oxidation and reduction reactions, particularly those allowing control of regio-and stereochemistry. The 2003 literature provides the vast majority of the content, with selected earlier references where needed to put the more recent work into context. The drive towards cleaner, cheaper, and more environmentally friendly reaction processes, as well as improved control over chemo-, regio-and stereoselectivity, particularly enantioselectivity, are continuing themes. Particular highlights include major developments in catalytic asymmetric conjugate reduction of enones, 1 particularly when incorporated into tandem conjugate reduction/aldol processes. 2 1 Oxidation reactions Alkene epoxidationThe development of more efficient catalytic methods for alkene epoxidation continues to receive intense interest. 3,4 For example, Stack has reported two new catalysts employing commercially available peracetic acid as co-oxidant.[Mn II (mcp)(CF 3 SO 3 ) 2 ]-catalyzed epoxidation proceeds via an electrophilic species, allowing regioselective epoxidation of carvone (Scheme 1), albeit with low diastereoselectivity. 5 This system does not display the selectivity for cis-alkenes over transalkenes that is typical for Mn(salen) epoxidations. In a second contribution, the same workers have developed a simple iron catalyst, [((phen) 2 (H 2 O)Fe III ) 2 (m-O)](ClO 4 ) 4 (phen ~phenanthroline) which will epoxidize a range of alkenes, including terminal ones (Scheme 2). 6 With allylic alcohol substrates, alcohol oxidation competes, while allyl acetate and cyclohexenone do not react. Styrenes can give product mixtures.Use of cleaner co-oxidants is an important focus. Epoxidations employing hydrogen peroxide for this purpose are attractive since the by-product is water, and progress in this area has been reviewed. 7,8 A highly efficient and recyclable

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In situ alcohol oxidation-Wittig reactions using N-methoxy-N-methyl-2-(triphenylphosphoranylidine)acetamide: application to the synthesis of a novel analogue of 5-oxo-eicosatetraenoic acid

Cited by 31 publications

References 13 publications

Tandem Oxidation Processes Using Manganese Dioxide: Discovery, Applications, and Current Studies

Tandem Oxidation Processes Using Manganese Dioxide: Discovery, Applications, and Current Studies

Tandem-, Domino- and One-Pot Reactions Involving Wittig- and Horner-Wadsworth-Emmons Olefination

3 Synthetic methods : Part (ii) Oxidation and reduction methods

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