55878-91-6Relevant academic research and scientific papers
Generation of Stable Ruthenium(IV) Ketimido Complexes by Oxidative Addition of Oxime Esters to Ruthenium(II): Reactivity Studies Based on Electronic Properties of the Ru?N Bond
Shimbayashi, Takuya,Okamoto, Kazuhiro,Ohe, Kouichi
supporting information, p. 16892 - 16897 (2017/12/02)
The reaction of an oxime ester with [Ru(PPh3)3X2] proceeded smoothly at room temperature to afford a stable RuIV ketimido complex as oxidative adduct. The structure of the complex was unambiguously determined by X-ray crystallographic analysis, which showed an almost linear Ru?N?C array. The electronic properties of the nitrogen atom were estimated by DFT calculations, and the results suggested double-bond character of the Ru?N bond. Kinetic studies and consideration of the substituent effect on the oxime ester led to the proposal of a reaction mechanism involving oxidative addition, which could proceed by N,O-chelating coordination to the Ru center prior to N?O bond cleavage. The obtained Ru ketimido complex could be transformed into a ruthenacycle by C?H activation by a concerted metalation–deprotonation mechanism in dichloromethane/methanol. Ru ketimido complexes with a tethered alkyne or alkene moiety underwent chloroamination of unsaturated C?C bonds followed by C?H activation, which resulted in the formation of a ruthenacycle. Considering the LUMO of an isolated Ru ketimido complex, the chloroamination should proceed by a synchronous 1,3-dipolar cycloaddition-type mechanism. Insight into the character and reactivity of Ru ketimido complexes will be helpful for developments in the catalytic transformation of oxime esters.
2-Substituted 1,3-Benzoxathiolium Tetrafluoroborates as Efficient Acylating Agents for N,N-Dialkylarylamines
Cadamuro, Silvano,Degani, Iacopo,Fochi, Rita,Gatti, Antonella,Regondi, Valeria
, p. 544 - 547 (2007/10/02)
2-Substituted 1,3-benzoxathiolium tetrafluoroborates were used as efficient masked acylating agents for N,N-dialkylarylamines in a two-step reaction.In most of the cases intermediate 2,2-disubstituted 1,3-benzoxathioles were obtained in high yields (about 90percent) and their hydrolysis afforded the corresponding ketones in almost quantitative yields.The new procedure offers the following advantages: (1) the reaction conditions are mild; (2) the acylation proceeds selectively at the para-position as referred to the dialkylamino group; (3) the introduction of a tertiary group is easily accomplished.
