75265-80-4Relevant articles and documents
Oxidative addition of allylic substrates to coordinatively unsaturated ruthenium compounds, [Ru(η5-C5Me5)(η-amidinate)]: Preparation, structure elucidation, and catalysis of novel ruthenium (IV)-η3-allyl complexes
Kondo, Hideo,Kageyama, Akira,Yamaguchi, Yoshitaka,Haga, Masa-Aki,Kirchner, Karl,Nagashima, Hideo
, p. 1927 - 1937 (2007/10/03)
Oxidative addition reactions of allylic halides, acetates, and carbonates with [Ru(η5-C5Me5)(η-amidinate)] [amidinate: iPrNC(Me)=NiPr (1a), 1BuNC(Ph)=N1Bu (1b)], which shows signs of coordinative unsaturation, gave novel cationic π-allyl ruthenium(IV) species. The compounds [Ru(η3-allyl)(η5-C5Mes)(η 2-amidinate)]+X- were isolated by anion exchange of the products (X = PF6, BF4, BPh4), and were characterized by spectroscopic analysis. The crystallography of two of the [Ru(η3-allyl)(η5-C5Mes)(η 2-amidinate)] +X- revealed a four-legged piano stool structure in which two nitrogen atoms in the amidinate ligand and two carbon atoms in the η3-allyl ligands occupy the positions of four legs; the orientation of the η3-allyl ligand was endo. Although cyclic voltammograms of the precursor, [Ru(η5-C5Me5)(η-amidinate)], indicated possible oxidative addition of organic halides other than allylic halides to [Ru(η5-C5Me5)(η-amidinate)], only allylic halides gave the corresponding Ru(IV) products. The importance of prior coordination of the carbon-carbon double bond of allylic substrates was evidenced by NMR observation of the intermediate in the reaction of 1a or 1b with allyl acetate. Addition of nucleophiles such as PhLi, dimethyl methylsodiomalonate, and piperidine to the [Ru(η3-allyl)(η5-C5Me 5)(η2-amidinate)]+X- gave rise to allylation of these nucleophiles and regeneration of [Ru(η5-C5Me5)(η-amidinate)]. The reactions of allyl methyl carbonate with nucleophiles were also achieved by catalysis of either [Ru(η5C5Me5)(η-amidinate)] or [Ru(η3-allyl)(η5-C5Me 5)(η2-amidinate)]+X-.
Palladium-Catalyzed Decarboxylative Allylic Alkylation of Allylic Acetates with β-Keto Acids
Tsuda, Tetsuo,Okada, Masahiro,Nishi, Sei-ichi,Saegusa, Takeo
, p. 421 - 426 (2007/10/02)
In the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium, β-keto acids react with allylic acetates at ambient temperature to produce α-allylic ketones in good yields with quantitative decarboxylation.This palladium-catalyzed decarboxylative allylic alkylation of allylic acetates with β-keto acids is characterized by high regio- and stereoselectivity.Allylation of β-keto acid takes place at the carbon atom bearing a carboxyl group.Allylic alkylation of allylic acetate with β-keto acid occurs at the less substituted end of the allyl group.The resultant carbon-carbon double bond of the α-allylic ketone has the E configuration.Allylic alkylation of lactone 25 with benzoylacetic acid proceeds preferably with retention of configuration, indicative of trans attack of the enolate on the (?-allyl)palladium intermediate from the opposite side of palladium even in the coexistence of free carboxylic acids.
Facile Generation of a Reactive Palladium(II) Enolate Intermediate by the Decarboxylation of Palladium(II) β-Ketocarboxylate and Its Utilization in Allylic Acylation
Tsuda, Tetsuo,Chujo, Yoshiki,Nishi, Sei-ichi,Tawara, Kunio,Saegusa, Takeo
, p. 6381 - 6384 (2007/10/02)
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