om010042b_si_001.pdf (1.2 MB)
BINOL Compounds of Group 13
journal contribution
posted on 2001-05-04, 00:00 authored by Soheila Chitsaz, Bernhard NeumüllerThe reaction of GaMe3 with 1 equiv of (S)-BINOL ((S)-(−)-2,2‘-dihydroxy-1,1‘-binaphthyl)
in toluene at reflux conditions gave after recrystallization from THF the chiral organogallium
alkoxide [(THF)MeGa((S)-BINOLate)]2 (1). In contrast treatment of PhCH2InCl2 with 1 equiv
of Li2((S)-BINOLate) in THF at reflux and recrystallization from DME led not to the desired
organoindium alkoxide but to [{(DME)Li}3{In((S)-BINOLate)3}]·2DME (2·2DME). The
similar salt [{(DME)Li}3{In((S)-BINOLate)3}]·0.75THF (2·0.75THF) was obtained by direct
synthesis of InCl3 with 3 equiv of Li2((S)-BINOLate) in THF at 65 °C and recrystallization
from DME. The compounds 1 and 2 are readily soluble only in donor solvents, while the
potassium derivative [{(toluene)2K}3{In((S)-BINOLate)3}]·2toluene (3·2toluene), obtained in
the reaction of InCl3 with 3 equiv of K2((S)-BINOLate) in toluene, is very soluble in toluene
and n-hexane. 1−3 have been characterized by their NMR, IR, and MS spectra as well as
by X-ray analyses. Compound 1 is dimeric with a Ga2O2 four-membered ring. 2 consists of
a tetranuclear InO6Li3 skeleton in which every Li+ ion is coordinated by one additional DME
ligand. The basic structural motif in 3, an InO6K3 core, is comparable to the skeleton in 2.
However, the coordinated toluene molecules of every K+ ion in 3 are bound by mainly
electrostatic metal−π-electron interactions.