Halodiazirines as Valuable Reagents for the Synthesis of Halocyclo­propanes

Abstract

Halodiazirines emerged as very useful reagents in photochemically- or thermally-mediated cyclopropanation reactions with alkenes. This Short review highlights the synthetic applications of these reagents as precursors of halocarbenes with various alkenes.

Cyclopropanation of Alkenes with Halodiazirines as Halocarbene Precursors in Continuous Flow

“…[14] However, the applications of halodiazirines are not yet fully developed in organic synthesis. [5,15] Since diazirines show greater bench stability, lower toxicity, and lower explosibility than diazoalkanes, it is therefore important to further expand and develop their potential in organic synthesis. [16] Recently, continuous flow chemistry has gained a lot of attention as a practical tool in photochemical carbene chemistry.…”

“…Numerous applications have also been reported as the use of diazirines in medicinal chemistry [12] as well as in surface chemistry for immobilizing analytes [13] and in polymer cross‐linking [14] . However, the applications of halodiazirines are not yet fully developed in organic synthesis [5,15] . Since diazirines show greater bench stability, lower toxicity, and lower explosibility than diazoalkanes, it is therefore important to further expand and develop their potential in organic synthesis [16] .…”

“…There have been few articles on the cyclopropanation of halodiazirines so far (Scheme 1). [15] They report the thermolysis reactions of chlorodiazirines under high pressure (Scheme 1, eq a) [27] or photolysis under energy‐consuming, dangerous, and expensive mercury lamps for long reaction times (Scheme 1, eq b) [28] . Moreover, studies on the synthesis of halocyclopropanes have only been reported with a limited scope of substrates.…”