Ruthenium catalysts for selective nucleophilic allylic substitution

Bruneau, Christian; Renaud, Jean‐Luc; Demerseman, Bernard

doi:10.1351/pac200880050861

Cited by 44 publications

(5 citation statements)

References 68 publications

(34 reference statements)

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“…The vast majority of allylic substitutions are carried out with palladium or iridium catalysts . Many other metals are also active, and we were encouraged to diversify in order to extend the scope of allyl fluoride chemistry. Despite the close similarities of many aspects of palladium and platinum organometallic chemistry, Pt-catalyzed allylic sustitutions are far less well developed and have never been applied to organofluorine substrates.…”

Section: Introductionmentioning

confidence: 99%

Platinum-Catalyzed Substitution of Allylic Fluorides

et al. 2012

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Allyl fluorides are reactive toward Pt-catalyzed alkylation with malonate and likewise toward N-and Onucleophiles under mild conditions. The reactivity of fluoride as a leaving group equals or exceeds that of the esters and carbonates commonly employed in allylic alkylation. The order of leaving-group ability with Pt catalysts was found to be F ≥ OCO 2 Me ≫ OBz ≥ OAc. This discouraged the application of platinum catalysts for the reverse reaction, fluorination of allylic substrates. Fluoride displacement involves predominant or complete retention of configuration in all the observed cases, and this was confirmed as a general feature of Pt catalysis, the stereochemical integrity being as high or higher as in Pd catalysis for the examples chosen.

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Section: Introductionmentioning

confidence: 99%

Platinum-Catalyzed Substitution of Allylic Fluorides

et al. 2012

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“…Regioselectivity of the nucleophilic attack by nucleophiles at the nonsymmetrically substituted η 3 -complexes is mainly governed by the nature of the metal. Thus, Pd complexes are preferentially attacked at the less substituted terminus, ,,, whereas Mo, W, , Ru, Rh, and Ir − exhibit the opposite tendency, affording the branched isomer as the major product. However, in the Rh-catalyzed reactions with symmetrical substrates, the nucleophile enters at the site to which the leaving group was orriginally attached .…”

Section: Resultsmentioning

confidence: 99%

A Modular Approach to Aryl-C-ribonucleosides via the Allylic Substitution and Ring-Closing Metathesis Sequence. A Stereocontrolled Synthesis of All Four α-/β- and d-/l-C-Nucleoside Stereoisomers

et al. 2011

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Iridium(I)-catalyzed allylation of the enantiopure monoprotected copper(I) alkoxide, generated from (S)-5a, with the enantiopure allylic carbonates (R)-9a,b has been developed as the key step in a new approach to C-nucleoside analogues. The anomeric center was thus constructed via a stereocontrolled formation of the C-O rather than C-C bond with retention of configuration. The resulting bisallyl ethers 15a,b (≥90% de and >99% ee) were converted into C-ribosides 29a,b via the Ru-catalyzed ring-closing metathesis, followed by a diastereoselective dihydroxylation catalyzed by OsO(4) or RuO(4) and deprotection. Variation of the absolute configuration of the starting segments 5a and 9a,b allowed a stereocontrolled synthesis of all four α/β-D/L-combinations.

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“…Usually, the alcohols are converted into acetate, carbonate, or halide for smooth allylation and alkylation reactions. 3 In addition to the Pd-catalysed Tsuji–Trost reaction, 1 a ,1 b which proceeds through palladium π-allyl intermediate, complexes of palladium, 4 platinum, 5 ruthenium, 6 indium, 1 c molybdenum, 7 gold, 8 and rhodium 9 have been used as catalysts for this kind of allylation reaction. The palladium-based catalysts predominantly afford the linear allylated products, although some diallyl products are also obtained.…”

Section: Introductionmentioning

confidence: 99%