From amine to ruthenaziridine to azaallyl: unusual transformation of di-(2-pyridylmethyl)amine on ruthenium

Abstract

The complexation of di-(2-pyridylmethyl)amine to RuHCl(PPh₃)₃ affords the salt [RuH{κ³N-fac-1,3-di-(2-pyridylmethyl)amine}(PPh₃)₂]Cl. Reaction with potassium tert-butoxide at room temperature yields the unusual ruthenaziridine complex RuH{κ³C^alkNN^py-1,3-di-(2-pyridylmethyl)amine}(PPh₃)₂, where the central nitrogen atom, adjacent alkyl carbon, and pyridine arm coordinate to the metal, leaving the second pyridine arm uncoordinated. Surprisingly, heating of this ruthenaziridine complex with concomitant H₂ formation affords the ruthenium azaallyl complex RuH(κ³N-1,3-di-(2-pyridyl)-2-azaallyl)(PPh₃)₂. This is a rare example of a 4d metal complex containing the azaallyl ligand. X-Ray crystal structures and NMR characterization of all three compounds are presented herein.