Does anything like this covalent concerted bond exchange reaction exist?
$$\ce{W=X + Y=Z -&gt;[\mathrm{cat}] W=Y + X=Z}$$ is known as olefin metathesis, achieved using Grubbs/Hoyveda/Fürstner catalysts.

Water-soluble Ru catalysts have been prepared in the Grubbs group (DOI).