Abstract Approach was developed underlain by the use of fluorinated diazocompounds to the synthesis of derivatives of α-trifluoromethyl-α-hydroxycarboxylic acids and their phosphorus-containing analogs, α-trifluoromethyl-α-hydroxyphosphonic acids. Methyl 2- diazo-3, 3, 3-trifluoropropionate and diethyl 1-diazo-2, 2, 2-trifluoroethylphosphonate under the action of catalytic quantities of dirhodium tetraacetate Rh 2 (OAc) 4 easily inserted into ...