Correlation of stereoselectivity and ion response in electrospray mass-spectrometry. electrospray ionization-mass spectrometry as a tool to predict chemical behavior?
Several alkali cation complexes of chiral alkoxymethyl-substituted acylsilanes, prepared in situ by the admixture of alkali iodides to acylsilane sample solutions, were investigated by electrospray ionization-mass spectrometry. Competition experiments suggest that the relative complex stabilities of such species in acetonitrile solution follow the order [Formula: see text], which is different from the order of the relative stabilities of the complexes in the gas phase ([Formula: see text]) as qualitatively determined by a tandem mass spectrometry-type experiment. Additionally, a rough correlation of relative ion responses in the mass spectrometry with relative stereoselectivities-derived from chelate-controlled reactions performed with the respective silanes-was found. The latter observation suggests that the electrospray ionization-mass spectrometry technique is a potentially useful method to predict chemical behavior, and it demands little experimental effort.
Organisch-chemisches Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.
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Chapeaurouge
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Bigler
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Schäifer
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Bienz