Absolute rate constants for some hydrogen atom abstraction reactions by a primary fluoroalkyl radical in waterElectronic supplementary information (ESI) available: Tables of kinetic data and plots of kinetic data. See http://www.rsc.org/suppdata/ob/b3/b313757k/
作者:Li Zhang、Joseph Cradlebaugh、Grzegorz Litwinienko、Bruce E. Smart、Keith U. Ingold、William R. Dolbier, Jr.
DOI:10.1039/b313757k
日期:——
flash photolysis and competitive kinetic methods have been used to measure the absolute bimolecular rateconstants for hydrogenatomabstraction in water from a variety of organic substrates including alcohols, ethers, and carboxylic acids by the perfluoroalkyl radical, *CF(2)CF(2)OCF(2)CF(2)SO(3)(-) Na(+). Comparison, where possible, of these rateconstants with those previously measured for analogous
Rates of hydrideabstractions from j3-silyl-, j3-germyl-, and B-stannyl-substituted silanes (HSiMeZ(CHz- MMe3), M = Si, Ge, Sn) and related compounds by diarylcarbenium ions have been measured. The intermediate silicenium ions, produced in the rate-determining step, are stabilized by hyperconjugation, but the effects are much smaller than in comparable carbenium ions. ~~ ~~ ~~
Rhodium-catalyzed decomposition of alpha-vinyldiazoesters in the presence of silanes, alcohols, ethers, amines, and thiols have been shown to produce the corresponding alpha-silyl, alpha-hydroxy, alpha-alkoxy, alpha-amino, and alpha-thioalkoxy esters in generally good yield with a complete retention of the stereochemistry of the double bond of the diazo precursor. An extension of the process in homochiral series has also been devised using either a chiral auxiliary attached to the ester function or achiral alpha-vinyldiazoesters and Doyle's chiral catalyst Rh-2(MEPY)(4). In the former approach, pantolactone as chiral auxiliary gave diastereoselectivities of up to 70%, while the second approach produced the desired allylsilane with ee as high as 72%. On the other hand, Rh-2(MEPY)(4)-catalyzed insertion into the O-H bond of water led to poor or no enantioselectivity in good agreement with recent literature reports.
Danilkina, L. P.; Ostroukhova, O. K., Journal of general chemistry of the USSR, 1989, vol. 59, # 10.2, p. 2061 - 2063