- Directed ortho-metalation, a new insight into organosodium chemistry
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Finely dispersed metallic sodium in combination with an alkyl chloride RCcan replace organolithium reagents in the ortho-metalation of aromatic compounds (see scheme). The in situ generated base is consumed as soon as it is formed, which avoids Wurtz coupling, the usual side reaction, and the handling and storage of highly reactive alkyl sodium bases. Reaction conditions are mild, the reaction is easy to scale up, and the reagents needed are inexpensive.
- Gissot, Arnaud,Becht, Jean-Michel,Desmurs, Jean Roger,Pevere, Virginie,Wagner, Alain,Mioskowski, Charles
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Read Online
- Method for orthometalation of a carbocyclic aromatic derivative bearing at least an electron donor group
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The invention concerns a method for orthometalation of a carbocyclic aromatic derivative bearing at least an electron donor group, characterised in that it consists in reacting said carbocyclic aromatic derivative with an efficient amount of at least one alkaline metal in the presence of a compound of formula (I): RX, wherein: R represents a hydrocarbon radical having 1 to 20 carbon atoms which can be a saturated or unsaturated, linear or branched, acyclic aliphatic radical; a saturated or unsaturated, monocyclic or polycyclic cycloaliphatic radical; a saturated or unsaturated, linear or branched aliphatic radical bearing a cyclic substituent; and X represents a bromine or chlorine atom.
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Page column 9
(2010/01/31)
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- Synthesis of Substituted Dibenzophospholes. Part 2. Syntheses of Intermediate Biphenyls and Quaterphenyls
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A general procedure for synthesis of 4",6'-dialkoxy-2',2"-diamino-m-quaterphenyls has been established.Copper(I) t-butoxide is used to prepare 2,6-dinitrophenyls from 1,3-dinitrobenzene and aryl iodides.One of the nitro-groups is then exchanged for a methoxy-group by sodium methoxide in hexamethylohosphoramide; the resulting 2-methoxy-6-nitrobiphenyls are then iodinated in the 5-position.Ullmann coupling then gives the dinitroquaterphenyls which are reduced to the diamines.An alternative route from 2,2',4,4'-tetranitrobiphenyl was explored; arylation was easy but alkoxydenitration was indiscriminate.Some 71 new derivatives of biphenyl, terphenyl, and quterphenyl are reported.
- Cornforth, John,Sierakowski, Andrew F.,Wallace Timothy W.
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p. 2299 - 2316
(2007/10/02)
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