Iron-Catalyzed Cycloaddition Reaction of Diynes and Cyanamides at Room Temperature
作者:Chunxiang Wang、Dongping Wang、Fen Xu、Bin Pan、Boshun Wan
DOI:10.1021/jo400057t
日期:2013.4.5
An iron-catalyzed [2 + 2 + 2] cycloaddition reaction of diynes and cyanamides at room temperature is reported. Highly substituted 2-aminopyridines were obtained in good to excellent yields with high regioselectivity. Insights toward the reaction process were investigated through in situ IR spectra and control experiments. In this iron-catalyzed cycloaddition reaction, the active iron species was generated only in the presence of both alkynes and nitriles. The lower reaction temperature, broad substrates scope, and inversed regioselectivity make it a complementary method to the previously developed iron catalytic system.
Regioselective Iron-Catalyzed [2 + 2 + 2] Cycloaddition Reaction Forming 4,6-Disubstituted 2-Aminopyridines from Terminal Alkynes and Cyanamides
作者:Nathan A. Spahn、Minh H. Nguyen、Jonas Renner、Timothy K. Lane、Janis Louie
DOI:10.1021/acs.joc.6b02374
日期:2017.1.6
redox-active pyridine dialdimine (PDAI) ligands catalyze the cycloaddition of two terminalalkynes and one cyanamide. The reaction is both chemo- and regioselective, as only 4,6-disubstituted 2-aminopyridine products are formed in moderate to high yields. Isolation of an iron azametallacycle (4) suggests that catalyst deactivation occurs with a large excess of cyanamide over longer reaction times. Fe-catalyzed