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Full details of the theoretical study are reported on the lithium--halogen reaction of 1,1-dihaloalkenes with methyllithium and the nucleophilic substitution reaction of the resulting alpha-halo alkenyllithium compounds. The thermodynamic preferences were predicted correctly by the energy differences of the products.

The extension of carbocyclizations of C-tethered N-acyloxyiminium ions with substituted alkene, alkyne and allene tethers to give novel azacyclic ring systems is reported. It is shown that the carbocyclization of mixed allene/alkene/alkyne tethers favors reaction of the allene, leading to the preferential formation of relatively strained hydrooxazinones rather than the corresponding hydroindoles.

The m-chloroperoxybenzoate (m-CPBA) anion is highly efficient nucleophilic epoxidating reagent for strongly deactivated olefins containing two electron-withdrawing groups at the same carbon, under mild conditions. It is observed that the combined use of m-CPBA with catalytic or stoichiometric amounts of KOH or K2CO3 allows the selection formation of oxirans only from strongly gem-disubstituted olefines by electron withdrawing agents.

The alkene radical cations undergoing nucleophilic attack are formally planar and achiral, but their association with the anion in a contact ion pair raises the possibility of enantiostereogenicity of the precursor radical if trapping takes place before equilibrium of the various possible ion pairs.