Electrochemical bromofunctionalization of alkenes in a flow reactor

Abstract

The bromination of organic molecules has been extensively studied to date, yet there is still a demand for safe and sustainable methodologies. Hazardous reagents, selectivity, low atom economy and waste...

Selective Electrochemical Dibromination of Terpenes and Naturally Derived Olefins

“…[39,[42][43] The electrochemical bromofunctionalization of alkenes including the generation of 1,2-vicinal dihalides have attracted special attention. [44][45][46][47][48][49][50] Many great protocols have been reported recently for the electrochemical bromination of alkenes featuring direct electrochemical bromination, [44][45] electrocatalytic bromination [48] and bromination via linear paired electrosynthesis. [46,49] Recently, the electrochemical bromofunctionalization of alkenes in a flow reactor was also reported.…”

“…[47] While these methods are widely applicable and provide good to excellent yields, they often utilize dangerous bromine sources, such as HBr, [45,47] and depleting metal electrodes. [44][45][46][47][48] To overcome these drawbacks, a novel method for the transhalogenation of numerous alkenes via an electron shuttle reaction was recently reported by our group. [49] Nevertheless, while the electrochemical bromination of simple alkenes was extensively researched, the functionalization of naturally derived compounds and especially the dibromination of terpenes and terpenoids casts only very few examples.…”

“…[46,49] Recently, the electrochemical bromofunctionalization of alkenes in a flow reactor was also reported. [47] While these methods are widely applicable and provide good to excellent yields, they often utilize dangerous bromine sources, such as HBr, [45,47] and depleting metal electrodes. [44][45][46][47][48] To overcome these drawbacks, a novel method for the transhalogenation of numerous alkenes via an electron shuttle reaction was recently reported by our group.…”

“…Furthermore, constant current conditions in combination with carbon‐based electrodes allow an easy and safe operation by simply switching on or off the electrochemical current [39,42–43] . The electrochemical bromofunctionalization of alkenes including the generation of 1,2‐vicinal dihalides have attracted special attention [44–50] . Many great protocols have been reported recently for the electrochemical bromination of alkenes featuring direct electrochemical bromination, [44–45] electrocatalytic bromination [48] and bromination via linear paired electrosynthesis [46,49] .…”

“…Many great protocols have been reported recently for the electrochemical bromination of alkenes featuring direct electrochemical bromination, [44–45] electrocatalytic bromination [48] and bromination via linear paired electrosynthesis [46,49] . Recently, the electrochemical bromofunctionalization of alkenes in a flow reactor was also reported [47] . While these methods are widely applicable and provide good to excellent yields, they often utilize dangerous bromine sources, such as HBr, [45,47] and depleting metal electrodes [44–48] .…”