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Carbanions indenyl

Reaction of the cationic cyclooctadiene iridium complex [Ir( n -COD)(PMe3)3]+[Cl] with carbanions afforded236 different products depending on the nature of the carbanion. For resonance stabilised carbanions (indenyl, allyl, benzyl) the products were (2-substituted cyclooct-5-en-l-yl)tris(trimethylphosphine) complexes derived from nucleophilic attack on one of the coordinated double bonds of the diene. One such complex, [(2-benzylcyclooct-5-en-l-yl)tris(trimethylphosphine)iridium], (19), was characterised by X-ray diffraction. For non-... [Pg.346]

SRNl substitution include ketone enolates,183 ester enolates,184 amide enolates,185 2,4-pentanedione dianion,186 pentadienyl and indenyl carbanions,187 phenolates,188 diethyl phosphite anion,189 phosphides,190 and thiolates.191 The reactions are frequently initiated by light, which promotes the initiating electron transfer. As for other radical chain processes, the reaction is sensitive to substances that can intercept the propagation intermediates. [Pg.1055]

The studies by Tolbert on indenyl carbanions were extended to the 2 halogenated anions. In this interesting cases halide ejection was shown to override the electron transfer chemistry and an hypovalent intermediate of the carbene or allene type is formed leading to C-H insertion products [137, 138, 139],... [Pg.119]

The photocyclization of (108) to (110) is another ten-electron process, this time involving a system isoconjugate with an odd hydrocarbon anion. The first step is probably a photochemical conrotatory closure to (109). The transition state, being of anti-Huckel type in a fused 6-5 system with ten delocalized electrons, should be antiaromatic. The intermediate (109), isoconjugate with a linear C7 carbanion, was not isolated but underwent rearrangement, probably by a 1,5 sigmatropic shift via a transition state isoconjugate with the indenyl anion (111). [Pg.470]

A range of carbanions have been silylated with TBDMS triflate, including allylic, alkynyl, and indenyl systems. Functionalized TBDMS-substituted diazoacetates are prepared by C-silylation of unsubstituted diazoacetates using TBDMS triflate in combination with Hiinig s base (eq 47). The crude silyl diazoacetate can be directly oxidized without further purification to give silylglyoxylates (eq 48). ... [Pg.133]

A relatively limited set of carbanions derived from hydrocarbons has been used as nucleophiles in reactions. In the photoinitiated reactions of indenyl, 1- and 2-phenyl-, 2,3- and 1,3-diphenylindenyl anions, products of mono-, di-, and triphenylation are formed. A higher yield of substitution is obtained with the 1,3-diphenyHndenyl anion, which affords 1,1,3-triphenyhndene as well as 1,2,3-triphenyUn-... [Pg.923]


See other pages where Carbanions indenyl is mentioned: [Pg.103]    [Pg.60]    [Pg.71]    [Pg.172]    [Pg.735]    [Pg.148]    [Pg.1428]    [Pg.386]    [Pg.111]    [Pg.94]    [Pg.106]    [Pg.106]    [Pg.106]    [Pg.735]    [Pg.248]    [Pg.606]    [Pg.4]   
See also in sourсe #XX -- [ Pg.327 ]

See also in sourсe #XX -- [ Pg.327 ]

See also in sourсe #XX -- [ Pg.327 ]




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