4613-10-9Relevant academic research and scientific papers
Triphosgene and DMAP as Mild Reagents for Chemoselective Dehydration of Tertiary Alcohols
Ganiu, Moshood O.,Cleveland, Alexander H.,Paul, Jarrod L.,Kartika, Rendy
supporting information, p. 5611 - 5615 (2019/08/01)
The utility of triphosgene and DMAP as mild reagents for chemoselective dehydration of tertiary alcohols is reported. Performed in dichloromethane at room temperature, this reaction is readily tolerated by a broad scope of substrates, yielding alkenes preferentially with the (E)-geometry. While formation of the Hofmann products is generally favored, a dramatic change in alkene selectivity toward the Zaitzev products is observed when the reaction is carried out in dichloroethane at reflux.
Stereoselectivity in the Condensation Reactions of 1-Phenylethyl Alkyl and Phenyl Ketones with Organometallic Reagents
Alvarez-Ibarra, Carlos,Arjona, Odon,Perez-Ossorio, Rafael,Perez-Rubalcaba, Alfredo,Quiroga, Maria L.,Santesmases, Maria J.
, p. 1645 - 1648 (2007/10/02)
Stereochemical results of the condensation reactions of a series of ketones, PhCHMeCOR (R= Me, Et, Pri, But, Ph), with various organomagnesium and organolithium derivatives in ethers as solvents are reported.Results are accounted for on the basis of competition between two transition states which may adopt either Karabatsos- or Felkin-type conformations according to the nature of R, the reagent nucleophilicity, and the polarity of solvent.Polar and steric analysis of this reaction allows highly stereoselective syntheses of diastereoisomeric α-phenylalkanols to be devised.
The Stereochemistry of Condensation Reactions of (+/-)-3-Phenylbutan-2-one with Phenylmetallic Compounds as a Function of the Reagent Nucleophilicity
Arjona, Odon,Perez-Ossorio, Rafael,Perez-Rubalcaba, Alfredo,Quiroga, Maria L.
, p. 452 - 453 (2007/10/02)
The influence of changing the metall and adding electrophilic catalysts or iron(III) and copper(I) salts on the stereochemical path of the nucleophilic addition of organometallics to (+/-)-3-phenylbutan-2-one is discussed.
Stereochemistry of Addition to the Carbonyl Group. Part 17. Study of the Factors affecting Asymmetric Induction in Condensation Reactions of Methyl- and Phenyl-magnesium Bromide with Chiral Carbonyl Compounds
Arjona, Odon,Perez-Ossorio, Rafael,Perez-Rubalcaba, Alfredo,Quiroga, Maria L.
, p. 597 - 603 (2007/10/02)
The dependence of the stereoselectivity upon the nature of the chiral carbonyl compound , the solvent, and the concentration ofthe reactive species for various condensation reactions of phenyl- and methyl-magnesium bromide at 30 degC is reported.The stereochemical results have been interpreted on the basis of the generalized Curtin-Hammett principle and according to a trigonal-type transition state (Perez-Ossorio model).No effect of the concentration of the reactive species on the product ratio was observed.An unexpected influence of the solvent was observed in the condensation of (4) with phenylmagnesium bromide.A good linear correlation between stereoselectivity and the ET parameter of the solvent was obtained.The explanation offered here takes into account the steric selection of the transition states and a further differentiating effect of the solvent polarity on them.A slight influence of solvent polarity on reactions of (5) with Grinard reagents was also noticed.
