Cyclopropanation of Alkenes with Halodiazirines as Halocarbene Precursors in Continuous Flow

Hoang-Minh To and Thierry Ollevier

Chem. Eur. J. 2024, e202303969

http://www.doi.org/10.1002/chem.202303969

The cyclopropanation reaction of alkenes with photolytically-generated chlorocarbenes from chlorodiazirines is reported as an effective way to prepare substituted 3-chloro-3-aryl-cyclopropanes. This practical and efficient approach allows the synthesis of various 3-chloro-3-aryl-cyclopropanes (32 examples) in continuous flow in 5-minute residence time under light-emitting diode (LED) irradiation. The conditions using 380 nm LED irradiation were successfully extended to the synthesis of substituted 3-bromo-3-aryl-cyclopropanes (3 examples).