34292-93-8Relevant articles and documents
Formation of the bisulfite anion (HSO3 -, m/z 81) upon collision-induced dissociation of anions derived from organic sulfonic acids
Jariwala, Freneil B.,Wood, Ryan E.,Nishshanka, Upul,Attygalle, Athula B.
experimental part, p. 529 - 538 (2012/08/28)
In the negative-ion collision-induced dissociation mass spectra of most organic sulfonates, the base peak is observed at m/z 80 for the sulfur trioxide radical anion (SO3 -·). In contrast, the product-ion spectra of a few sulfonates, such as cysteic acid, aminomethanesulfonate, and 2-phenylethanesulfonate, show the base peak at m/z 81 for the bisulfite anion (HSO3 - ). An investigation with an extensive variety of sulfonates revealed that the presence of a hydrogen atom at the β-position relative to the sulfur atom is a prerequisite for the formation of the bisulfite anion. The formation of HSO3 - is highly favored when the atom at the β-position is nitrogen, or the leaving neutral species is a highly conjugated molecule such as styrene or acrylic acid. Deuterium-exchange experiments with aminomethanesulfonate demonstrated that the hydrogen for HSO3 - formation is transferred from the β-position. The presence of a peak at m/z 80 in the spectrum of 2-sulfoacetic acid, in contrast to a peak at m/z 81 in that of 3-sulfopropanoic acid, corroborated the proposed hydrogen transfer mechanism. For diacidic compounds, such as 4-sulfobutanoic acid and cysteic acid, the m/z 81 ion can be formed by an alternative mechanism, in which the negative charge of the carboxylate moiety attacks the α-carbon relative to the sulfur atom. Experiments conducted with deuterium-exchanged and deuterium-labeled analogs of sulfocarboxylic acids demonstrated that the formation of the bisulfite anion resulted either from a hydrogen transfer from the β-carbon, or from a direct attack by the carboxylate moiety on the α-carbon. Copyright
A New Class of "Tethered" Ruthenium(II) Catalyst for Asymmetric Transfer Hydrogenation Reactions
Hannedouche, Jerome,Clarkson, Guy J.,Wills, Martin
, p. 986 - 987 (2007/10/03)
Ruthenium dimer 4 is converted directly to monomeric asymmetric transfer hydrogenation catalyst 2 under the conditions employed for ketone reduction. Using 0.25 mol % of either 4 or 0.5 mol % of 2 in formic acid/triethylamine, it is possible to achieve ketone reduction in quantitative conversion and with ee's as high as 98%. Complex 2 is a robust "single-reagent" catalyst which offers significant scope for modification toward specific substrates. The synthesis and applications of an analogous complex derived from (1R,2S)-norephedrine are also described. Copyright
KINETICS AND MECHANISM OF THE ALKALINE HYDROLYSIS OF SUBSTITUTED PHENYL PHENYLALKANE- AND PHENYLALKENESULFONATES
Vizgert, R. V.,Enya, V. I.
, p. 926 - 929 (2007/10/02)
The effect of the bond multiplicity and the distance between the aromatic ring and the sulfur atom of the sulfo group in a series of substituted phenyl benzene-, α-phenylmethane-, 2-phenylethane-, and 2-phenylethylenesulfonates on the kinetics and mechani
