The addition of a beta C-H bond to the formyl group of aldehydes to olefins took place with the aid of Ru(H)(2)(CO)(PPh3)(3) as a catalyst. Several olefins can be used in the catalytic reaction of conjugate enals. The presence of a sterically hindered substituent at the ortho position of benzaldehyde and the presence of an electron donating substituent appear to be important factor in accomplishing the desired coupling reaction.