A Direct Synthesis of Vinylphosphonium Salts from α‐Trimethylsilyl Ylides and Non‐Enolizable Aldehydes

McNulty, James; Das, Priyabrata

doi:10.1002/chem.200801358

Cited by 10 publications

(9 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, the fragmentation of 9 occurs to give TMSCl with regeneration of PPh 3 ; meanwhile, the trapping of :CF 2 by PPh 3 gives the ylide. In Path B, a phosphonium salt 10 , which is formed via a single-electron transfer (SET) mechanism, undergoes a chloride ion-promoted desilylation reaction to afford Ph 3 P=CF 2 [42–43]. However, we could not rule out the possibility of chloride ion-activation in these processes due to the involvement of intermediates 9 and 10 in the proposed mechanisms.…”

Section: Resultsmentioning

confidence: 98%

Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine

Wang¹,

Li²,

Ni³

et al. 2014

Beilstein J. Org. Chem.

View full text Add to dashboard Cite

Summary Background: 1,1-Difluoroalkenes cannot only be used as valuable precursors for organic synthesis, but also act as bioisosteres for enzyme inhibitors. Among various methods for their preparation, the carbonyl olefination with difluoromethylene phosphonium ylide represents one of the most straightforward methods. Results: The combination of (chlorodifluoromethyl)trimethylsilane (TMSCF2Cl) and triphenylphosphine (PPh3) can be used for the synthesis of gem-difluoroolefins from carbonyl compounds. Comparative experiments demonstrate that TMSCF2Cl is superior to (bromodifluoromethyl)trimethylsilane (TMSCF2Br) and (trifluoromethyl)trimethylsilane (TMSCF3) in this reaction. Conclusion: Similar to many other Wittig-type gem-difluoroolefination reactions in the presence of PPh3, the reaction of TMSCF2Cl with aldehydes and activated ketones is effective.

show abstract

Section: Resultsmentioning

confidence: 98%

Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine

Wang¹,

Li²,

Ni³

et al. 2014

Beilstein J. Org. Chem.

View full text Add to dashboard Cite

show abstract

“…We supposed that, when phosphorus atom in ylide becomes more electropositive due to the replacement of aryl substituents by alkyls, the Peterson type elimination would be more effective. We expected that in the reaction between tributyl[(trimethylsilyl)methylene]phosphorane and aldehydes, even the aliphatic ones, ethenylphosphonium salts should be formed exclusively in analogy to the work of McNulty 15 .…”

Section: Resultsmentioning

confidence: 98%

“…In the literature it was postulated that the steric approach control intermediate -betaine -may be formed not as the primary but as the secondary one 15 . It was assumed that it was the result of the formation of the respective oxaphosphetane intermediate as the primary product which may equilibrate with betaine.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of alkenylphosphonium salts from tributyl[(trimethylsilyl)methylene]phosphorane and enolisable aldehydes

Majewski

Łukaszewicz

2010

Collect. Czech. Chem. Commun.

View full text Add to dashboard Cite

Efficient synthesis of alkenylphosphonium salts via treatment of enolizable aliphatic aldehydes with tributyl[(trimethylsilyl)methylene]phosphorane has been described. The simple way for preparation of tributyl[(trimethylsilyl)methylene]phosphorane is also presented.The alkenylphosphonium salts have been extensively investigated for the last four decades of the past century and the results of these investigations have been a subject of numerous reviewes 1,2 . These phosphonium salts have found wide application in organic chemistry after it was settled out that their reaction with nucleophiles results in phosphorus ylides, which subsequently may be subjected to produce, via Wittig olefination, carboand heterocyclic systems in a stereoselective manner 3 . This powerful methodology was applied in the elegant synthesis of such compounds as E-or Z-N-allylpyrroles 4 , tetraalkyl (1Z,3Z)-buta-1,3-diene-1,2,3,4-tetracarboxylates 5 , precursor of (-)-supidine 6 and functionalized coumarins 7 . Alkenylphosphonium salts have been used in the radical addition to give products which were further converted to a variety of useful synthetic intermediates 8 , as an electron-deficient dienophile in Diels-Alder cycloaddition 9 , and in polymerization to produce antimicrobal polymers 10 . Additionally, triarylalkenylphosphonium salts have been investigated as the potential reagents for radioactive labeling of immunoglobins and other proteins 11 .The alkenylphosphonium salts are conveniently synthesized from the β-substituted alkylphosphonium salts through β-elimination reaction in the presence of a base 12 , by the addition of the titanium-substituted ylide spe-

show abstract

“…In turn, McNulty and Das proposed that the E ‐stereoselectivity of the Peterson reaction between a silylphosphonium ylide and aromatic aldehydes can also be rationalized in terms of the formation of erythro ‐betaine via an erythro ‐oxaphosphetane intermediate, which undergoes syn‐elimination under kinetic control .…”

Section: Introductionmentioning

confidence: 99%

Mechanism of Formation of Aromatic Vinylphosphonium Salts via the Peterson Olefination

2013

View full text Add to dashboard Cite

The mechanism of the reaction of tributyl[(trimethylsilyl)methylene]phosphorane with benzaldehyde and its p‐substituted analogues has been examined. It has been found that the electronic nature of the p‐substituents in aromatic aldehydes strongly influences the stereochemical and kinetic outcome of the Peterson olefination whereas temperature substantially affects their Hammett correlation. This indicates that the Peterson olefination is a multistep reaction involving the formation of at least an oxyanion/betaine and a carbanion as intermediates. In turn, moderate Z‐selectivity might be the result of “steric approach intermediate control”; however, E‐selectivity seems to result from the silicon–oxygen interaction and interactions of steric substituents in competing erythro‐ and threo‐betaines.

show abstract

A Direct Synthesis of Vinylphosphonium Salts from α‐Trimethylsilyl Ylides and Non‐Enolizable Aldehydes

Abstract: New route: The reaction of α‐silylated ylides with non‐enolizable aldehydes proceeds by selective Peterson‐type elimination, in contrast to prior literature reports. The described synthesis provides a direct route to synthetically useful vinylphosphonium salts (see scheme).

Cited by 10 publications

References 34 publications

Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine

Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine

Synthesis of alkenylphosphonium salts from tributyl[(trimethylsilyl)methylene]phosphorane and enolisable aldehydes

Mechanism of Formation of Aromatic Vinylphosphonium Salts via the Peterson Olefination

Contact Info

Product

Resources

About