Mono- and trifluorination of the thiazole ring of 2,5-diarylthiazoles using N-fluorobenzenesulfonimide (NFSI)
摘要:
Fluorination of select 2,5-diarylthiazoles using the N-F reagent N-fluorobenzenesulfonimide (NFSI) has led to the formation of both the anticipated 4-fluorothiazole as well as a unique 4,4,5-trifluorothiazole. Selective monofluorination is best achieved using bromobenzene as solvent at 155 degrees C, while trifluorination is best achieved by performing the reaction without solvent at 135-140 degrees C. An X-ray crystal structure has been obtained on one of the trifluorinated products. (C) 2012 Elsevier Ltd. All rights reserved.
Direct Arylation of Simple Azoles Catalyzed by 1,10-Phenanthroline Containing Palladium Complexes: An Investigation of C4 Arylation of Azoles and the Synthesis of Triarylated Azoles by Sequential Arylation
amounts of azoles, selective C5 monoarylation was achieved by using the same catalytic system. Subsequent efforts demonstrated that C5 arylated azoles undergo exclusive C2 arylationusing [Pd(phen)2]PF6 as the catalyst with galvinoxyl as an additive. Finally, unprecedented C4 arylation reactions of 2,5-diaryl-azoles occur by using the new catalytic system to give the corresponding triarylated products in
Mono- and trifluorination of the thiazole ring of 2,5-diarylthiazoles using N-fluorobenzenesulfonimide (NFSI)
作者:Julie M. Hatfield、Cheryl K. Eidell、Chad E. Stephens
DOI:10.1016/j.tetlet.2012.12.052
日期:2013.2
Fluorination of select 2,5-diarylthiazoles using the N-F reagent N-fluorobenzenesulfonimide (NFSI) has led to the formation of both the anticipated 4-fluorothiazole as well as a unique 4,4,5-trifluorothiazole. Selective monofluorination is best achieved using bromobenzene as solvent at 155 degrees C, while trifluorination is best achieved by performing the reaction without solvent at 135-140 degrees C. An X-ray crystal structure has been obtained on one of the trifluorinated products. (C) 2012 Elsevier Ltd. All rights reserved.