Palladium(II)-catalyzed exchange and isomerization reactions. 14. Kinetics and stereochemistry of the isomerization and water exchange of 2-(methyl-d3)-4-methyl-1,1,1,5,5,5-hexafluoro-3-penten-2-ol in aqueous solution catalyzed by PdCl42-. Two new mechanistic probes for catalytic chemistry