A Scalable Procedure for Light-Induced Benzylic Brominations in Continuous Flow
David Cantillo, Oscar de Frutos, Juan A. Rincon, Carlos Mateos* and C. Oliver Kappe*
*Centro de Investigación Lilly S.A., Avda. de la Industria 30, 28108 Alcobendas-Madrid, Spain; University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria, Email: mateos_gutierrez_carloslilly.com, oliver.kappeuni-graz.at
D. Cantillo, O. de Frutos, J. A. Rincon, C. Mateos, C. O. Kappe, J. Org. Chem., 2014, 79, 223-229.
DOI: 10.1021/jo402409k (free Supporting Information)
In a continuous-flow protocol for the bromination of benzylic compounds with only a small excess of N-bromosuccinimide, the radical reactions were activated with a readily available household compact fluorescent lamp (CFL) using a simple flow reactor design based on transparent fluorinated ethylene polymer tubing. All of the reactions were carried out using acetonitrile as the solvent, thus avoiding hazardous chlorinated solvents such as CCl4.
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