- Deprotonation-alkylation of alkyl cyanides under sonochemical conditions
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Deprotonation-alkylation of n-alkyl cyanides can be readily effected by an alkyl halide in the presence of sodium in a one pot procedure. Yields are generally better than in the usual methods, and the overall reaction conditions have important advantages
- Berlan,Delmas,Duee,Luche,Vuiglio
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p. 1253 - 1260
(2007/10/02)
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- Process for introducing alkyl radicals into carbon chains having a functional group and compounds prepared by said process
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Process for introducing a substituent selected from branched- or straight-chain alkyl radicals having from 1 to 12 carbon atoms, aralkyl or cycloalkyl radicals in which the alkyl moiety has from 1 to 4 carbon atoms, into a carbon chain bearing a stable functional group the said carbon chain having at least one proton in α-position in relation to this functional group, process whereby, in a first step, this carbon chain is reacted with a complex base comprising a mixture of alkali metal amide and alkali metal alcoholate suspended in an anhydrous organic solvent to provide temporarily a carbanion, then in a second step this carbanion is reacted in an anhydrous organic solvent with an alkyl, aralkyl or cycloalkyl halide corresponding to the substituent to be introduced.
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- Wanderungstendenzen cyclischer, polycyclischer und methylverzweigter Alkylreste bei der Beckmann-Umlagerung
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The migration aptitudes of polycyclic bridgehead groups, cycloalkyl groups as well as of β-, γ- and δ-branched alkyl groups in the Chapman variant of the Beckmann rearrangement were determined.From these data it is concluded that at transition state 2 the migrating group is not resembling a planarised carbenium ion R+, but rather a pentacoordinated carbonium ion structure.Because only small geometrical changes occur in the migrating group vertical stabilisation of charge at transition state is believed to have significant influence on the migration aptitudes.
- Langhals, Heinz,Ruechardt, Christoph
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p. 3831 - 3854
(2007/10/02)
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