Bromonium ion transfer reagents: Synthesis, mechanism of bromine(+) transfer to olefins and X-ray structure.

摘要

Compound 69, 1,2-bis(2′-pyridylethynyl)benzene bromonium triflate was synthesized and the mechanism of its reactions with various acceptors was studied. The kinetic study showed that the bromination promoted by compound 69 is second order overall, first order in both the bromonium ion complex and acceptor. It is proposed that there is a first reversible dissociation of compound 69 from the di-coordinated bromonium complex to a mono-coordinated intermediate 109.; A synthetic route to compound 3,5-bis-[2-(3,5,3″,5 ″-tetramethyl-1,1′: 3′,1 ″-terphenyl-5′-yl)-naphthalen-1-yl]-pyridine, 70, a target compound designed as a potential chiral catalyst capable of mediating asymmetric bromination, is described, although the target compound was not obtained in this study.; Bis(2,4,6-sym collidine)bromonium perchlorate, 71, was synthesized and recrystallized and its structure was determined by X-ray diffraction. (Abstract shortened by UMI.)