5432-54-2Relevant academic research and scientific papers
Cinchona alkaloid phase-transfer catalysts revisited: Influence of substituted aryl groups on the enantioselectivity of glycine ester enolate alkylation
Kumar, Sanjeev,Ramachandran, Uma
, p. 7022 - 7028 (2007/10/03)
We report herein, the influence of substituted aryl groups in quaternary ammonium salts derived from cinchona alkaloids on enantioselectivity of the alkylation of glycine ester enolates.
Palladium-catalyzed arylation of α,α-disubstituted arylmethanols via cleavage of a C-C or a C-H bond to give biaryls
Terao, Yoshito,Wakui, Hiroyuki,Nomoto, Michiyo,Satoh, Tetsuya,Miura, Masahiro,Nomura, Masakatsu
, p. 5236 - 5243 (2007/10/03)
The palladium-catalyzed arylation of α,α-disubstituted arylmethanols with aryl halides proceeds not only via C-H bond cleavage at the ortho-position, but also via cleavage of the sp2-sp3 C-C bond with the liberation of ketones (β-carbon elimination) to give the corresponding biaryls. Both reactions appear to occur through common arylpalladium(II) alcoholate intermediates. The results of systematic studies with respect to which C-C or C-H bond is preferentially cleaved in the arylation are reported. Among the important findings is the selective elimination of ortho-substituted aryl groups even from aryl(diphenyl)methanols due to steric reasons. Thus, various biaryls having ortho-substituents can be produced efficiently by treatment of the corresponding aryl(diphenyl or dimethyl)methanols with aryl bromides and chlorides.
NEW METHODOLOGY IN DETERMINING EVIDENCE FOR SINGLE ELECTRON TRANSFER IN THE REACTION OF GRIGNARD REAGENTS WITH KETONES
Zhang, Yunshi,Wenderoth, Bernd,Su, Wei-Yang,Ashby, E. C.
, p. 29 - 38 (2007/10/02)
A new method is reported to determine the existence of single electron transfer in the reaction of Grignard reagents with ketones.The method involves the determination of pseudo-first order rate constants by following the rate of disappearance of the paramagnetic intermediate and relating the rate of this disappearance to the appearance of the product.The reactions of methyl-, phenyl- and t-butyl-Grignard reagents with substituted benzophenones were examined.This method should be applicable to a wide range of organometallic reactions.
Aroyl Anion Trapping Reactions. A Preliminary Study of Direct Nucleophilic Aroylation by Means of Low Temperature, in situ (CH3)nC6H5 nLi/CO Systems.
Seyferth, Dietmar,Wang, Wei-Liang,Hui, Rihard C.
, p. 1651 - 1654 (2007/10/02)
Results of studies of the in situ nucleophilic aroylation of PhCO2Me, Me3CCO2Me and Ph2CO by several low temperature ArLi/CO systems (Ar = C6H5, p-CH3C6H4, o-CH3C6H4, 2,6-(CH3)2C6H3 and 2,4,6-(CH3)3C6H2) are reported.The experiments with C6H5Li were unsuccessfull and the best results were obtained with 2,6-(CH3)2-C6H3Li.
