2-Lithio-3,3-dimethyl-2-oxazolinyloxirane: Carbanion or Azaenolate?
Vito Capriati*, Saverio Florio*, Renzo Luisi, Filippo Maria Perna and Agnese Spina
Dipartimento Farmaco-Chimico, Università di Bari, Consorzio Interuniversitario Nazionale Metodologie e Processi Innovativi di Sintesi C.I.N.M.P.I.S., Via E. Orabona 4, I-70125 Bari, Italy; J. Org. Chem., 2008, 73 (24), pp 9552–9564.
Structure, Configurational Stability and Stereodynamics in Solution
During this work, Vito Capriati, Saverio Florio and colleagues at the University of Bari in Italy used in situ Infrared (IR) and Nuclear Magnetic Resonance (NMR) spectroscopy together to give a better insight into the stability of lithium salt and to ultimately answer the question:
“Is the lithium salt more like an organolithium or is it more like an azaenolate?”
Previous studies had shown seemingly conflicting results. On the one hand, the lithium salt would racemize extremely quickly at very cold temperatures, which was corroborated from computer modeling. On the other hand, the same molecule was observed to be stable at -78°C for hours during a deuteration experiment.
To see the results of the work done at the University of Bari, see the white paper on Metal Catalyzed Transformations Using In Situ Spectroscopy. This white paper highlights examples from academia where in situ IR spectroscopy has been used as an enabling tool to uncover key parameters in each metal catalyzed transformation investigation.