C−N and C−C Coupling Reactions:  Preparation of New N-Heterocyclic Ruthenium Derivatives

Abstract

Three novel types of complexes containing heterocyclic ligands are prepared by condensation of the allenylidene ligand of [Ru(η5-C5H5)(CCCPh2)(CO)(PiPr3)]BF4 (1) with propargylamines. Complex 1 reacts with propargylamine to give initially [Ru(η5-C5H5){C(CHCPh2)NHCH2C⋮CH}(CO)(PiPr3)]BF4 (2). Treatment of 2 with KOH in methanol affords the bicyclic derivative Ru(η5-C5H5){4-methylidene-6,6-diphenyl-2-azabicyclo[3.1.0]hex-2-en-1-yl}(CO)(PiPr3) (3). The formation of 3 takes place via the intermediate Ru(η5-C5H5){C(CHCPh2)NCH2C⋮CH}(CO)(PiPr3) (4), which is isolated when the deprotonation of 2 is carried out in tetrahydrofuran as solvent. In contrast to propargylamine, the addition of 1,1-diethylpropargylamine to 1 leads to the dihydropyridiniumyl derivative [Ru(η5-C5H5){2,2-diethyl-5-diphenylidene-2,5-dihydropyridinium-6-yl)(CO)(PiPr3)]BF4 (5) in a one-pot synthesis. Complex 1 also reacts with N-methylpropargylamine. The reaction affords [Ru(η5-C5H5){C(CHCPh2)N(CH3)CH2C⋮CH}(CO)(PiPr3)]BF4 (6). Treatment of 6 with sodium methoxide, at −78 °C, gives a 1:1 mixture of the dihydronaphthopyrrolyl diastereomers (R Ru S C,S Ru R C)-[Ru(η5-C5H5){9-phenyl-4,4a-dihydronaphtho[2,3-c]-1-pyrrolyl})(CO)(PiPr3) (7a) and (R Ru R C,S Ru S C)-[Ru(η5-C5H5){9-phenyl-4,4a-dihydronaphtho[2,3-c]-1-pyrrolyl})(CO)(PiPr3) (7b). Complexes 3 and 5 and the enantiomeric mixture 7a have been characterized by X-ray diffraction analysis.

Ogle Atlas of Classical Novae. I. Galactic Bulge Objects

“…It declined quickly on timescales of t 2 = 12 days and t 3 = 23 days (Morgan, Ringwald & Prigge 2003). Early spectra showed emission lines of H I, Fe II, and Na I, typical for Fe II novae (Buil 2002;Duerbeck, Sterken & Fu 2002). The later spectral and photometric evolution was summarized by Morgan et al (2003).…”

Hubble Space Telescope Imaging of the Expanding Nebular Remnant of the 2006 Outburst of the Recurrent Nova RS Ophiuchi

“…Such models lead to the ejection of somewhat lower masses at higher velocities than those for models of CN (typically 5000 km s −1 and 10 −8 − 10 −6 M ⊙ respectively for RNe). Spectroscopy of RS Oph has indeed shown Hα line emission with FWHM = 3930 km s −1 and FWZI = 7540 km s −1 on 2006 February 14.2 (t = 1.37 days, Buil 2006).…”

Synthesis, characterization and catalytic studies of iron(III), cobalt(II), nickel(II) and copper(II) complexes containing triphenylphosphine and β-diketones

“…Mild and efficient aromatic coupling have been reported. Recently, a number of transition metal complexes have been found to catalyze aryl-aryl coupling reactions [11][12][13][14][15][16][17][18]. b-diketonato transition metal complexes have been the subject of many different investigations ranging from synthetic, kinetic and structural topics, to catalysis and electron transfer processes [19][20][21][22][23].…”