Cupric Halide-Mediated Intramolecular Halocyclization of N-Electron-Withdrawing Group-Substituted 2-Alkynylanilines for the Synthesis of 3-Haloindoles
作者:Zengming Shen、Xiyan Lu
DOI:10.1002/adsc.200900609
日期:2009.12
efficient method for the synthesis of 3-haloindoles has been developed. Both 3-chloro- and 3-bromoindole derivatives can be obtained in high yields by the reaction of N-electron-withdrawinggroup-substituted2-alkynylanilines with cupric halide in dimethyl sulfoxide (DMSO) within a short period of time. Investigation of the reaction mechanism reveals that two equivalents of cupric halide are necessary
New Access to 2,3-Disubstituted Quinolines through Cyclization of <i>o</i>-Alkynylisocyanobenzenes
作者:Michinori Suginome、Takeshi Fukuda、Yoshihiko Ito
DOI:10.1021/ol991133w
日期:1999.12.1
[GRAPHICS]o-Alkynylisocyanobenzenes underwent nucleophile-induced intramolecular cyclization to give 2,3-disubstituted quinoline derivatives in high yields. In addition to the oxygen and nitrogen nucleophiles such as methanol and diethylamine, the nucleophilic carbon of the enolate of malonate induced the cyclization effectively. Reaction of 1,4-di(trimethylsilylethynyl)-2,3-diisocyanobenzene with methanol afforded 2,9-dimethoxy-1,10-phenanthroline in good yield.
Synthesis of 2-Alkoxy(aroxy)-3-substituted Quinolines by DABCO-Promoted Cyclization of <i>o</i>-Alkynylaryl Isocyanides
Diversified 2-alkoxy- and 2-aroxy-3-substituted quinolines were synthesized from o-alkynylaryl isocyanides and alcohols and phenols promoted by DABCO, respectively. The reaction was initiated by nucleophilic addition of DABCO to isocyanide and subsequent cycliztion, leading to a DABCO-quinoline-based adduct as the reactive intermediate, followed by substitution of the DABCO moiety with oxygenated nucleophiles.