Lithiated Fluorinated Styrene Oxides: Configurational Stability, Synthetic Applications, and Mechanistic Insight

摘要: The configurational stability of some lithiated fluorinated styrene oxides has been investigated. Chemical studies have shown that in ethereal solvents alpha-lithiated ortho-, meta-, and para-fluorostyrene (2-Li, alpha-5-Li, alpha-6-Li) are all configurationally stable the reaction time scale, whereas para-trifluoromethylstyrene (9-Li, 13-Li, 14-Li) unstable. Optically active oxiranyllithiums 2-Li 9-Li, could be stereospecifically generated quenched with electrophiles. corresponding derivatives were then successfully subjected to regiospecific ring-opening reactions amines give beta-amino alcohols a stereodefined quaternary carbinol center, which useful synthons medicinal chemistry. barriers inversion calculated (Eyring equation) for 14-Li by determining enantiomeric ratios after electrophilic quenching on aging enantioenriched organolithium different times THF; case activation parameters also determined. Mechanisms may responsible racemization undergo once discussed.