119548-50-4Relevant articles and documents
Iron-catalyzed, hydrogen-mediated reductive cyclization of 1,6-enynes and diynes: Evidence for bis(imino)pyridine ligand participation
Sylvester, Kevin T.,Chirik, Paul J.
supporting information; experimental part, p. 8772 - 8774 (2009/12/04)
(Chemical Equation Presented) The bis(imino)pyridine iron dinitrogen complex (iPrPDI)Fe(N2)2 catalyzes the hydrogen-mediated reductive cyclization of enynes and diynes with turnover frequencies comparable to those of established precious metal catalysts. Amino, oxygenated, and carbon-based substrates are readily cyclized to the corresponding hetero- and carbocycles with 5 mol % iron and 4 atm H2 at 23°C. Stoichiometric reactions between selected substrates and the iron compound under a N2 atmosphere established transfer dehydrogenation from an isopropyl aryl substituent to either the enyne or diyne substrate. In situ monitoring of the catalytic reaction by 1H NMR spectroscopy coupled with deuterium labeling experiments established rapid cyclization followed by turnoverlimiting hydrogenation. Copyright
Synthesis of cyclopropylpyrrolidines via reaction of N-allyl-N-propargylamides with a molybdenum carbene complex. Effect of substituents and reaction conditions
Harvey, Daniel F.,Sigano, Dina M.
, p. 2268 - 2272 (2007/10/03)
Previous studies have demonstrated that group 6 carbene complexes react with α,ω-enynes to form vinylcyclopropane derivatives in good to excellent yield, and that the length and composition of the tether between the alkyne and the alkene often has a dramatic impact on the viability of this reaction pathway. The reactivity of allylpropargyl amine derivatives with pentacarbonyl(1-methoxypentylidene)molybdenum(0) (14a) was investigated in order to provide further insight into the steric and electronic factors controlling this reaction. Treatment of allylpropargyl amines with 14a failed to produce the desired cyclization products while treatment of allylpropargyl amides with 14a led to the expected cyclopropylpyrrolidine systems in good to excellent yields. Higher yields are obtained when the reaction is conducted in a sealed vial in the presence of atmospheric oxygen.
