A domino three-component condensation of ortho-haloacetophenones with urea or amines: a novel one-pot synthesis of halogen-substituted quinolines
作者:Chuanmei Qi、Qingwei Zheng、Ruimao Hua
DOI:10.1016/j.tet.2008.12.039
日期:2009.2
Halogen-substituted quinolines have been synthesized in good yields by the condensation and cyclization of two molecules of ortho-haloacetophenones with urea or primary amines. The formation of halogen-substituted quinolines takes place through the unexpected catalyst-free cleavage of C(sp2)–X (X=Cl, Br), α-C(sp3)–H bonds and formation of C–C, C–N bonds in a selective manner. The attractive features
Enantioselective [3 + 2] annulation of N-heteroarenes with alkynes has been developed via a cobalt-catalyzed dearomative umpolung strategy in the presence of chiral ligand and reducing reagent. A variety of electron-deficient N-heteroarenes, including quinolines, isoquinolines, quinoxaline, and pyridines, and internal or terminal alkynes are employed in this reaction, showing a broad substrate scope