The present invention relates to derivatives of 2-aminothiazoles and 2-aminooxazoles in all its stereoisomeric forms, enantiomeric forms and mixtures in any ratio, and its physiologically acceptable salts and tautomeric forms showing peroxisome proliferators activator receptor (PPAR) delta agonist activity. These compounds are compounds of the formula I, in which the radicals are as defined, and their physiologically acceptable salts and processes for their preparations. The compounds are suitable for the treatment and/or prevention of disorders of fatty acid metabolism and glucose utilization disorders as well as of disorders in which insulin resistance is involved and demyelinating and other neurodegenerative disorders of the central and peripheral nervous system.