32116-66-8Relevant articles and documents
Biocatalytic Conversion of Cyclic Ketones Bearing α-Quaternary Stereocenters into Lactones in an Enantioselective Radical Approach to Medium-Sized Carbocycles
Morrill, Charlotte,Jensen, Chantel,Just-Baringo, Xavier,Grogan, Gideon,Turner, Nicholas J.,Procter, David J.
supporting information, p. 3692 - 3696 (2018/03/21)
Cyclic ketones bearing α-quaternary stereocenters underwent efficient kinetic resolution using cyclohexanone monooxygenase (CHMO) from Acinetobacter calcoaceticus. Lactones possessing tetrasubstituted stereocenters were obtained with high enantioselectivi
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-.
Highly regioselective alkylation at the more hindered α-site of unsymmetrical ketones by use of their potassium enolates. A comparative study with lithium enolates
Quesnel, Yannick,Bidois-Sery, Laure,Poirier, Jean-Marie,Duhamel, Lucette
, p. 413 - 415 (2007/10/03)
Alkylation of regioisomeric potassium enolates 4 and 6 obtained from corresponding silyl enol ethers 2 and 3 occurs at the most substituted site affording ketones 8. Alkylation of corresponding lithium enolates 5 and 7 occurs at the expected site affording ketones 8 or 9. As an application the one pot synthesis of spiroketones 13 from silyl enol ethers 12 is described.
