343608-08-2Relevant academic research and scientific papers
METHOD FOR THE ORGANOMETALLIC PRODUCTION OF ORGANIC INTERMEDIATE PRODUCTS BY HALOGEN-METAL EXCHANGE REACTIONS
-
Page/Page column 11, (2008/06/13)
The invention relates to a method for producing aryllithium compounds and to their reaction with suitable electrophiles to obtain compounds of formula (V), by reacting halogen aromatics (I) with lithium metal to obtain an aromatic lithium compound (II), which, as a lithiation agent, reacts with aromatic halogen compounds (III) in a halogen-metal exchange reaction to form the corresponding lithium aromatics (IV). Said aromatics can be reacted in an additional step with a corresponding electrophile to form the desired product (V). Said method is illustrated by equation (I), in which Ar represents phenyl, pyridyl or naphthyl, which are optionally substituted with a radical from the group consisting of methyl, primary, secondary or tertiary alkyl, cycloalkyl, phenyl, substituted phenyl, aryl, heteroaryl, alkoxy, dialkylamino, alkylthio, fluoro, bromo; Hal1 = fluorine, chlorine, bromine or iodine, Hal2 = chlorine, bromine or iodine; the groups X1-5 independently of one another represent either carbon, or the group XiRi (i = 1-5) represents nitrogen, or two respective adjacent groups XiRi, linked by a formal double bond, together represent O (furane), S (thiophene), NRH or NRi (pyrroles). The groups R1-5 represent substituents from the group containing hydrogen, methyl, primary, secondary or tertiary, cyclic or acyclic alkyl groups with 2 to 12 C atoms, in which optionally one or more hydrogen atoms are replaced by fluorine or chlorine, e.g. CF3, substituted cyclic or acyclic alkyl groups, alkoxy, dialkylamino, alkylamino, arylamino, diarylamino, phenyl, substituted phenyl, heteroaryl, substituted heteroaryl, alkylthio, arylthio, diarylphosphino, dialkylphosphino, alkylarylphosphino, dialkyl-, arylalkyl- or diarylaminocarbonyl, monoalkyl- or monoarylaminocarbonyl, CO2-, alkyl- or aryloxycarbonyl, hydroxyalkyl, alkoxyalkyl, fluorine or chlorine, nitro, cyano, aryl- or alkylsulphone, aryl- or alkylsulphonyl, or two respective groups R1-5 together can represent an aromatic, heteroaromatic or aliphatic fused ring.
