Quantum-chemical study on the mechanism of formation of geminal hydroxy thiols by reaction of 1,3-dihalopropan-2-ones with hydrogen sulfide

10.1007/s11178-008-1004-0

“…According to our previous data [7], rotamers A and B are the most favorable for elimination, while rotamer C is unfavorable. According to our previous data [7], rotamers A and B are the most favorable for elimination, while rotamer C is unfavorable.…”

“…The calculations were performed using Gaussian 98 software package [5] with 6-311+G(3df) basis set. The calculation details were described previously [7]. The calculation details were described previously [7].…”

“…According to the experimental data, the mechanism of formation of hydroxy thiols in reactions of halogenated ketones with hydrogen sulfide in the presence of hydrogen chloride is determined on the number of halogen atoms in the α-positions with respect to the carbonyl group and is almost independent of the halogen nature (F, Cl, Br) [7,8]. Therefore, the calculations were performed for chlorinated acetones.…”

“…The potential energy surface for the reaction of ketone I with H 2 S and HCl was analyzed following the pro- cedures described in [7,8] for trimolecular system I · HCl · H 2 S (V). It includes intermolecular proton shifts.…”

“…The potential energy surface for the reaction of ketone I with H 2 S and HCl was analyzed following the pro- cedures described in [7,8] for trimolecular system I · HCl · H 2 S (V). The activation barrier for the formation of structure III · HCl is 169.2 kJ/mol; i.e., it is lower by 14.2 kJ/mol than the barrier to analogous reaction of 1,3-dichloropropan-2-one [7]. The structures and principal geometric parameters of complex V are given in figure.…”