Patent ID: 7399876

Claim:
A process for preparing an alkenylphosphonic acid derivative by reacting a phosphonic acid derivative with an alkyne in the presence of a catalyst complex system, wherein the catalyst complex system comprises (a) nickel, (b) a phosphine having at least two trivalent phosphorus atoms and in addition (c) a phosphine having one trivalent phosphorus atom wherein the phosphine having at least two trivalent phosphorus atoms (b) is a phosphine of the formula (I) where R 1 , R 2 , R 3 and R 4 are each, independently of one another, a carbon-containing organic radical and X is a carbon-containing organic bridging group, wherein the phosphonic acid derivative is represented by the formula (II) where R 5 and R 6 are each, independently of one another, a carbon-containing organic radical, wherein the alkyne is represented by the formula (III) R 7 —C≡C—R 8 (III) where R 7 and R 8 are each, independently of on another, hydrogen or a carbon-containing organic radical and where R 7 and R 8 may optionally be joined to one another, and wherein the phosphine having one trivalent phosphorus atom (c) is a phosphine of the formula (IV) where R 9 , R 10 and R 11 are each, independently of one another, a carbon-containing organic radical.