Synthesis of heterocyclic analogues of Mosher's acid

Mosher’s acid and its derivatives are widely used to determine the enantiomeric excess of chiral compounds through derivatization. Increasing the diversity of the structures of Mosher’s acid analogs will increase the applicability and robustness of the method. We have prepared the first representatives of Mosher’s acid bearing 1,3-azole cores. It was found that C-silylazoles react smoothly with methyl 3,3,3-trifluoropyruvate in presence of F- anion to give the desired Mosher’s acid esters.