methods for the introduction of CF2H into heteroarenes. Herein we disclose a new strategy for the direct introduction of a difluoromethyl group into heteroarenes via the copper-mediated C-H oxidative difluoromethylation of heteroarenes with TMSCF2H. This mild and regioselective method enables the convenient synthesis of a range of difluoromethylated heteroarenes in high yields. The usage of 9,10-phenanthrenequinone
Nickel promoted switchable hydroheteroarylation of cyclodienes via C–H bond activation of heteroarenes
作者:Wei-Chih Lee、Wei-Chin Shih、Ting-Hsuan Wang、Yuhua Liu、Glenn P.A. Yap、Tiow-Gan Ong
DOI:10.1016/j.tet.2015.03.066
日期:2015.7
hydroheteroarylation of cyclicdienes via C–H bond activation of heteroarenes. In the presence of an N-heterocyclic carbene (NHC) ligand, hydroheteroarylation of cyclicdiene with azole afforded α-alkenyl-azole, forging a Heck-like product without using any external oxidant. Conversely, changing the ligand to PCy3 would switch this reaction manifold to afford the other isomeric β-alkenyl substituted azole.
5-(4′-Methoxyphenyl)-oxazole (MPO), originally reported as a synthetic compound, was isolated from fungal culture broth as an inhibitor of hatch and growth of Caenorhabditis elegans. Nineteen MPO derivatives were chemically synthesized, but showed no effect on C. elegans hatch and growth. These findings strongly suggested that the whole structure of MPO is essential for anti-C. elegans activity.
A Regel-type transition-metal-free direct C-2 aroylation of (benzo)oxazoles, (benzo)thiazoles and 1,3,4-oxadiazoles with acid chlorides catalyzed by N,N-dimethyl-4-aminopyridine (DMAP) is described. This methodology is effective with several aroyl and heteroaroyl chlorides affording the corresponding 2-ketoazoles in moderate to excellent yields.