ISSN:
0268-2605
Schlagwort(e):
lanthanoid metal
;
α,β-unsaturated ketone
;
aliphatic imine
;
homocoupling reaction
;
ytterbium dibromide
;
1,2-diol
;
1,6-diketone
;
1,2-diamine
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
A powerful reducing reagent, ytterbium dibromide (YbBr2), was synthesized by a new method using ytterbium metal and trimethylsilyl bromide (TMSBr) in tetrahydrofuran-hexamethylphosphoramide (THF-HMPA). YbBr2, thus formed in situ, causes coupling reactions of aliphatic ketones, α,β-unsaturated ketones and aliphatic aldimines to give bis-silylated 1,2-diols, 1,6-diketones and 1,2-diamines, respectively, in good yields. In the case of aliphatic ketimines, the corresponding reduced and silylated amines are obtained. In this solvent system, the trialkylsilyl moiety of trialkylsilyl bromide is converted to trialkylsilanes quantitatively. These results show that the Yb/TMSBr reagent generates YbBr2 in situ and the YbBr2 thus formed acts as a single-electron reductant for these coupling reactions.
Zusätzliches Material:
2 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/aoc.590090519
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