M. Lumbierres et al., The contribution made by triphenylphosphane in the putative catalysis by ruthenium species in conjugate additions of beta-dicarbonyl compounds, EUR J ORG C, (12), 2001, pp. 2321-2328
Triphenylphosphane catalyzes conjugate additions of beta -dicarbonyl compou
nds to pi -acceptor olefins and dialkyl azodicarboxylates. Formation of qua
ternary centers at the nucleophiles has been achieved. The catalytic action
of tris(triphenylphosphane)ruthenium(II) chloride and tetrakis(triphenylph
osphane)ruthenium(II) hydride is at least partially due to the phosphane li
gand.