Related Experiment Video
Updated: Jun 7, 2025

A Scalable Balz-Schiemann Reaction Protocol in a Continuous Flow Reactor
Published on: February 10, 2023
Synthesis of aryl fluorocyclopropanes from aryl fluorodiazirines and alkenes in continuous flow
Hoang-Minh To1, Shima Mirakhorli1, Thierry Ollevier1
1Département de Chimie, Université Laval, 1045 avenue de la Médecine, Québec, QC, G1V 0A6, Canada. thierry.ollevier@chm.ulaval.ca.
Abstract:
Photochemically induced generation of aryl fluorocarbenes from aryl fluorodiazirines and their subsequent [2+1] cycloaddition with alkenes was developed in continuous flow. The in situ generated electrophilic aryl fluorocarbene reacted with a range of alkenes enabling the synthesis of the corresponding 3-fluoro-3-aryl-cyclopropanes in a 5-minute residence time under 380-nm LED irradiation in continuous flow (20 examples). The scaled-up reaction of 3-fluoro-3-(4-chlorophenyl)-3H-diazirine with styrene under irradiation at 380 nm led to the fluorocyclopropane with a 77% yield, providing a throughput yield of 0.945 g h-1.
More Related Videos
07:06Continuous Flow Chemistry: Reaction of Diphenyldiazomethane with p-Nitrobenzoic Acid
Published on: November 15, 2017
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Related Concept Videos
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Preparation of Alkynes: Dehydrohalogenation
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ammonia. The reaction proceeds with the loss of two equivalents of hydrogen halide (HX) via two successive E2 elimination reactions.
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.