Results
Title

On the Configurational Stability of Chiral, Nonracemic Fluoro- and Iodo-[D<sub>1</sub>]Methyllithiums.

Authors

Kail, Dagmar C.; Malova Krizkova, Petra; Wieczorek, Anna; Hammerschmidt, Friedrich

Abstract

Enantiomerically pure fluoro-[D1]methyllithium and iodo-[D1]methyllithiums of up to 92 % ee were generated by transmetalation of the corresponding stannanes with MeLi in THF at various temperatures. The intermediate halo-[D1]methyllithiums were trapped with benzaldehyde or acetophenone already present in excess in the reaction mixture to either give halohydrins or to disintegrate to carbene. The fluoro-[D1]methyllithiums were found to be microscopically configurationally stable within the tested range of −95 to 0 °C, but chemically only stable at temperatures below −95 °C due to a rapidly increasing portion disintegrating to carbene. The iodo-[D1]methyllithiums were configurationally labile relative to the rate of addition to PhCHO at all temperatures tested (−95 to −30 °C). Disintegration to carbene interfered as well.

Subjects

CHIRALITY; METHYLLITHIUM; STANNANE; BENZALDEHYDE; HALOHYDRINS

Publication

Chemistry - A European Journal, 2014, Vol 20, Issue 14, p4086

ISSN

0947-6539

Publication type

Academic Journal

DOI

10.1002/chem.201304766