Amplification of Trichloroisocyanuric Acid (TCCA) Reactivity for Chlorination of Arenes and Heteroarenes via Catalytic Organic Dye Activation
作者:David A. Rogers、Adam T. Bensalah、Alvaro Tomas Espinosa、John L. Hoerr、Fares H. Refai、Amy K. Pitzel、Juan J. Alvarado、Angus A. Lamar
DOI:10.1021/acs.orglett.9b01414
日期:2019.6.7
electron-withdrawing groups are chlorinated in good to excellent yields (scalable to gram scale) using trichloroisocyanuricacid (TCCA) and catalytic Brilliant Green (BG). Visible-light activation of BG serves to amplify the electrophilic nature of TCCA, providing a mild alternative approach to acid-promoted chlorination of deactivated (hetero)aromatic substrates. The utility of the TCCA/BG system is demonstrated
Visible-light photocatalytic activation of N-chlorosuccinimide by organic dyes for the chlorination of arenes and heteroarenes
作者:David A. Rogers、Jillian M. Gallegos、Megan D. Hopkins、Austin A. Lignieres、Amy K. Pitzel、Angus A. Lamar
DOI:10.1016/j.tet.2019.130498
日期:2019.9
A variety of arenes and heteroarenes are chlorinated in moderate to excellent yields using N-chlorosuccinimide (NCS) under visible-light activated conditions. A screening of known organic dye photocatalysts resulted in the identification of methylene green as the most efficient catalyst to use with NCS. According to mechanistic studies described within, the reaction is speculated to proceed via a single
作者:Angela De Munno、Vincenzo Bertini、Nevio Picci、Francesca Iemma、Marco Pocci
DOI:10.3987/com-98-8144
日期:——
The key reagent 3,5-dichloro-4-pyridinecarbonitrile (1) was used to synthesize 4-aminomethylpyridine derivatives 3,5-disubstituted with various amino groups, very active as inhibitors of diamine oxidase. The study of the reaction allowed to discover conditions for the gradual substitution in good yields of the two chlorine atoms to give symmetrically and unsymmetrically disubstituted derivatives (3), or the substitution of the cyano group, or the formation of amidines. The reduction of the cyano to aminomethyl group in compounds (3) afforded the target bioactive products.
Microwave-assisted synthesis of 4-amino-3,5-dihalopyridines
4-Amino-3,5-dihalopyridines have been efficiently prepared via microwave-assisted nucleophilic aromatic substitution of 3,4,5-trihalopyridines using 1-1.1 equiv of primary and secondary amines. The reaction is also applicable to electron rich arylamines. (C) 2010 Elsevier Ltd. All rights reserved.