Cumyl phenyl sulfide forms bicumyl instead of cumyllithium upon reductive lithiation. Thiophenoxide as a leaving group in nucleophilic substitution by SET

Real-time mechanistic study of carbon nanotube anion functionalisation through open circuit voltammetry

The mechanism of the functionalisation of reduced single walled carbon nanotubes with organobromides was monitored by open circuit voltammetry throughout the reaction and further elucidated through a series of comparative reactions. The degree of functionalisation was mapped against the reagent reduction potential, degree of electron donation of substituents (Hammett parameter), and energies calculated, ab initio, for dissociation and heterolytic cleavage of the C-Br bond. In contrast to the previously assumed reduction/homolytic cleavage mechanism, the reaction was shown to consist of a rapid association of carbon-halide bond to the reduced nanotube as a complex, displacing surface-condensed countercations, leading to an initial increase in the net nanotube surface negative charge. The complex subsequently slowly degrades through charge transfer from the reduced single-walled carbon nanotube to the organobromide, utilizing charge, and the carbon-halide bond breaks heterolytically. Electron density on the C-Br bond in the initial reagent is the best predictor for degree of functionalisation, with more electron donating substituents increasing the degree of functionalisation. Both the mechanism and the new application of OCV to study such reactions are potentially relevant to a wide range of related systems.

Molecular rearrangement. 36. Selective alpha-CH oxidation of alkylarenes by nitrogen dioxide on thermolysis with nitramines

Thermolysis of 2,4,6-trichloro-N-nitroaniline 1 and N-methyl-2,4-dinitro-N-nitroaniline 2 each with primaryl alkylbenzenes led to the formation of acylbenzenes. Similar reactions with secondary alkylbenzenes afforded a mixture of acetophenone and aliphatic aldehydes. Use of tert-butylbenzene in this reaction yielded formaldehyde and 2,3-diphenyl-2,3-dimethylbutane. The mechanisms of the studied reactions are discussed.