A rapid injection NMR study of the reaction of organolithium reagents with esters, amides, and ketones.
Unexpectedly high rates of reaction between alkyllithium reagents and amides, compared to esters and ketones, were observed by Rapid Inject NMR and competition experiments. Spectroscopic investigations with 4-fluorophenyllithium (ArLi, mixture of monomer and dimer in THF) and a benzoate ester identified two reactive intermediates, a homodimer of the tetrahedral intermediate, stable below -100 °C, and a mixed dimer with ArLi. Direct formation of dimers suggested that the ArLi dimer may be the reactive aggregate rather than the usually more reactive monomer. In contrast, RINMR experiments with ketones demonstrated that the ArLi monomer was the reactive species.
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Kristin N
KN
Plessel
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Amanda C
AC
Jones
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Daniel J
DJ
Wherritt
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Rebecca M
RM
Maksymowicz
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Eric T
ET
Poweleit
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Hans J
HJ
Reich