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Continuous Flow Synthesis and Purification of Aryldiazomethanes through Hydrazone Fragmentation
Author(s) -
Lévesque Éric,
Laporte Simon T.,
Charette André B.
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201608444
Subject(s) - hydrazone , fragmentation (computing) , chemistry , flow chemistry , combinatorial chemistry , organic chemistry , computer science , catalysis , programming language
Electron‐rich diazo compounds, such as aryldiazomethanes, are powerful reagents for the synthesis of complex structures, but the risks associated with their toxicity and instability often limit their use. Flow chemistry techniques make these issues avoidable, as the hazardous intermediate can be used as it is produced, avoiding accumulation and handling. Unfortunately, the produced stream is often contaminated with other reagents and by‐products, making it incompatible with many applications, especially in catalysis. Herein is reported a metal‐free continuous flow method for the production of aryldiazomethane solutions in a non‐coordinating solvent from easily prepared, bench‐stable sulfonylhydrazones. All by‐products are removed by an in‐line aqueous wash, leaving a clean, base‐free diazo stream. Three successful sensitive metal‐catalyzed transformations demonstrated the value of the method.