Ruthenium alkynyl, carbene and alkenyl complexes containing pendant uracil groups: an investigation into the formation of alkenyl-phosphonio complexes

Dalton Trans. 2009 Nov 21:(43):9529-42. doi: 10.1039/b912855g. Epub 2009 Sep 18.

Abstract

The vinylidene complex [Ru(eta(5)-C(5)H(5))(PPh(3))(2)(=C=CHUr)][X] (X = PF(6), OTf, Ur = uracil) is a versatile precursor for a range of organometallic complexes containing pendant uracil groups. Using appropriate conditions the vinylidene complex may be selectively transformed into alkynyl Ru(-C[triple bond]CUr)(eta(5)-C(5)H(5))(PPh(3))(2), carbene [Ru(eta(5)-C(5)H(5))(PPh(3))(2)(=C{OMe}-CH(2)Ur)][X] and alkenyl-phosphonio species [Ru(E-CH=C{PPh(3)}Ur)(eta(5)-C(5)H(5))(PPh(3))(2)][X]. The synthesis of the related alkenyl-phosphonio complexes [Ru(E-CH=C{PPh(3)}R)(eta(5)-C(5)H(5))(PPh(3))(2)][X] (R = Ph, C(6)H(4)-3-OMe) is described; these undergo a further orthometallation reaction: the mechanism of this latter reaction appears to proceed via dissociation of a ruthenium-bound PPh(3) ligand.