Microwave radiation has been used to promote the addition of diphenylphosphine oxide to alkynes. The addition reactions were carried out using homogeneous and polymer-supported Group 9 catalysts such as (PPh3)(3)RhCl,[Rh(cod)Cl](2), and Rh/supported triphenyl phosphine. Solventless reactions involving terminal alkynes were extremely rapid, and high yields of the alkenylphosphine oxides were obtained in 2 min using microwave radiation. The hydrophosphinylation of internal alkynes such as 4-octyne was also rapid (20 min). For comparison addition reactions were carried out using conventional heating with the solid supported catalysts. The supported catalyst prepared from oligo(vinyl diphenylphosphine-co-vinyl diphenylphosphine oxide-co-vinyl chloride) was reused seven times to promote the addition of HP(O)Ph-2 to 1-heptyne with >90% conversion obtained in each case. (C) 2004 Elsevier B.V. All rights reserved.