Rolle von LiCl in Turbo-Hauser-Reagenz

[Zewski]

Hi,
Ich habe eine Frage bezüglich der TMP-Turbo-Hauser-Base, die zur Metallierung genutzt wird. Was bewirkt das LiCl?

[fleckenforscher]

Siehe Wikipedia

Knochel et al. proposed that LiCl increases the reactivity of Turbo-Grignard compounds RMgCl·LiCl (R = alkyl, aryl or vinyl) by giving the reactive bimetallic monomer a magnesiate character in sense of a solvent separated ion pair (SSIP) [Li(THF)4]+ [RMg(THF)Cl2]−.[1][11] In case of the above mentioned Turbo-Hauser bases where the alkyl group of a Grignard is replaced by an amido group (R = R'2N−) this hypothesis could not be confirmed because no SSIP [Li(THF)4]+ was detectible.

LiCl has been shown to increase solubility of RZnX reagent as well. Without LiCl, organozinc reagent remains on surface of zinc particle. With LiCl organozinc reagent forms a RZnX-LiCl complex, which is more soluble in THF.

Quelle: https://en.wikipedia.org/wiki/Turbo-Hauser_bases