Interconversion of contact and separated ion pairs in silyl- and arylthio-substituted alkyllithium reagents.
Ether-solvated contact and separated ion pairs (CIP and SIP) for two lithium reagents, tris(trimethylsilyl)methyllithium (1) and bis(3,5-bistrifluoromethylphenylthio)methyllithium (2), have been characterized and observed for the first time under conditions of slow exchange by NMR spectroscopy, and barriers to interconversion have been measured. A Saunders isotope perturbation experiment was used to support identification of the CIP and SIP species for 2.
Reich
Hans J
HJ
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI 53706, USA. reich@chem.wisc.edu
Sikorski
William H
WH
Thompson
Jennifer L
JL
Sanders
Aaron W
AW
Jones
Amanda C
AC