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Stereochemistry of olefination by phosphorus ylides

Publications associées (24)

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A new generation of "instant ylides": powder mixtures of phosphonium salts and potassium hydride as storable precursors to Wittig reagents

Qian Wang

Mixing a finely pulverized alkyltriphenylphosphonium salt and potassium hydride in 1:1 molar ratio gives a ready-to-use powder the components of which react rapidly when tert-Bu Me ether is added under stirring. When, in general after a few minutes, the ge ...

1996

About the structure of phosphorus ylides: electron distribution and geometry

Using 13C-chem. shifts as a probe for the electronic environment of carbon centers, triphenylphosphoniomethanide, the model case of a reactive phosphorus ylide, have much more zwitterion than PC double bond character. Triphenylphosphoniopropenide (tripheny ...

1990

Enhanced cis-selectivities in olefination reactions employing ylides with modified stationary groups

Whereas triphenylphosphonioethanide manifests unsatisfactory cis-selectivities (84.0-95.5%), tris(o,o'-difluorophenyl)- and tri-o-tolylphosphonioethanide react with aliph. or arom. aldehydes and, resp., 2-alkenals or 2-alkynals to afford the olefins with c ...

1986

The Wittig reaction: 30 years later

New and old ylide reactions are described and their mechanisms examd. A review with 12 refs. [on SciFinder (R)] ...

1983

New fun with old ylides

A review, with 10 refs., on the stereoselective synthesis of cis-C:C bonds via the Wittig reaction and its mechanism. [on SciFinder (R)] ...

1983

Phosphorus ylides

A review with 252 refs. [on SciFinder (R)] ...

Academic Press1978

Konfigurativ einheitliche Folgeprodukte aus Alkenylkalium-Zwischenstufen

Me groups adjacent to an olefinic double bond were metalated by KOCMe3 and BuLi without cis-trans isomerization. Thus, (E)-MeCH:-CHMe was metalated to give (E)-MeCH:CHCH2K (I) which reacted with ethylene oxide to give 41% (E)-MeCH:CH(CH2)3OH. If I was allo ...

1974

Chlorfluorcyclopropane durch Zweiphasenreaktion

Cl2CHF reacted with olefins in a 2-phase system to give 15-74% 1-chloro-1-fluorocyclopropanes. [on SciFinder (R)] ...

1973

Stereoselectivity of a,a'-diastereogenic reactions

A review of kinetic control in the diastereogenic formation of C-C bonds, Diels-Alder reactions, [2 + 2] cyclodimerization of olefins, syn preference in the formation of cyclopropanes from olefins and monosubstituted carbenes, reactions of organometallics ...

1971

Stereochemistry of the Wittig reaction

A review, with 91 refs., of stereoselectivity in reactions of stable and reactive ylids, and the application of stereoselective carbonyl olefinations. [on SciFinder (R)] ...

1970