Metal-free aminofluorination of α-diazo 2-benzopyran-4-one: convenient access to β-fluoramides

We have developed a convenient synthesis of a series of β-fluoramides in 65% yield. The process involved a tandem fluorination/Ritter reaction to synthesize β-fluoramides using α-diazo 2 H -benzopyran-4-one compounds. Selectfluor was used as the electrophilic fluoride source in acetonitrile to build the β-fluorinated quaternary carbon center and amide derivatives of 2 H -benzopyran-4-one in one step. The products N -(2-(2-fluoro-2,3-dihydro-3-oxobenzofuran-2-yl)propan-2-yl)acetamides were a series of bifunctional compounds with a 2-fluoro-2,3-dihydro-3-oxobenzofuran motif and amide groups. A new synthetic approach to β-fluoramides has been developed by a tandem fluorination/Ritter reaction using α-diazo 2 H -benzopyran-4-one compounds as the substrate and Selectfluor as the electrophilic fluoride source.