Diaryltriazenido Palladium(II) complexes derived from 1-(2-bromo-4-ethoxycarbonylphenyl)-3-phenyltriazenes

Publication date: Available online 24 July 2019Source: Journal of Organometallic ChemistryAuthor(s): Silvio Preusser, Paul R.W. Schönherr, Helmar Görls, Wolfgang Imhof, Sven Krieck, Matthias WesterhausenAbstract1-(2-Bromo-4-ethoxycarbonylphenyl)-3-phenyltriazene (1) can easily be deprotonated yielding the corresponding triazenides of lithium, silver, or triethylammonium. The equimolar metathesis reaction of [(Ph3P)2PdCl2] with these triazenides leads to the formation of [(Ph3P)2Pd(Ph-N3-C6H3-2-Br-4-COOEt)Cl] (3). The addition of another equivalent yields mixtures of [(Ph3P)2Pd(Ph-N3-C6H3-2-Br-4-COOEt)Cl] (3) and [(Ph3P)2Pd(Ph-N3-C6H3-2-Br-4-COOEt)2] (4). The reaction of 1-(2-bromo-4-ethoxycarbonylphenyl)-3-methyl-3-phenyltriazene (2) with one quivalent of [Pd(PPh3)2] leads to an oxidative addition of the C–Br-bond and the formation of [(Ph3P)2Pd{C6H3-2-(N=N–N(Me)Ph)-5-COOEt}Br] (5). The palladium atoms are in square planar environments.Graphical abstractPalladium triazenides are accessible by metathetical approaches tolerating halogeno- and ester functionalized aryl groups, whereas insertion of Pd into an aryl C–Br bond succeeds after protection of the triazene substructure via N-methylation.
Source: Journal of Organometallic Chemistry - Category: Chemistry Source Type: research