“…Bianchini and co-workers 10 have reported that bromination of 1d, 1g, and hexyne-2 (the closely related analogue of 1b) in 1,2-dichloroethane at room temperature gave mixtures of corresponding cis-and trans-dibromides with E/Z ratios ) 60/40, 57/43, and 100/ 0, respectively. Thus, the publication of Herges' results 16 motivates us to report the results of our DFT study of the addition reaction between molecular bromine and a number of symmetrical or unsymmetrical substituted alkynes 1 (R-CtC-R′), where R ) R′ ) H (1a), Me (1b), t-Bu (1c), or Ph (1d), or R ) H and R′ ) Me (1e), t-Bu (1f), or Ph (1g). The substituents were chosen for their different steric and electronic properties, as well as the opportunity to compare our calculated results with experimental data.…”