ja7b08734_si_001.pdf (14.2 MB)
Sodium Diisopropylamide in Tetrahydrofuran: Selectivities, Rates, and Mechanisms of Arene Metalations
journal contribution
posted on 2017-09-26, 00:00 authored by Russell
F. Algera, Yun Ma, David B. CollumSodium
diisopropylamide (NaDA)-mediated metalations of arenes in
tetrahydrofuran (THF)/hexane or THF/Me2NEt solutions are
described. A survey of >40 benzenoid- and pyridine-based arenes
with
a range of substituents demonstrates the efficacy and regioselectivity
of metalation. Metalations of activated disubstituted arenes and selected
monosubstituted arenes are rapid at −78 °C. Rate studies
of 1,3-dimethoxybenzene and related methoxylated arenes show exclusively
monomer-based orthometalations with two or three coordinated THF ligands.
Rate studies of the isotopic exchange of benzene and monosubstituted
arenes with weakly activating groups reveal analogous di- and trisolvated
monomer-based metalations. Cooperative inductive, mesomeric, steric,
and chelate effects are discussed.