Direct conversion of diazo compounds to fluoro derivatives

Metal-free aminofluorination of α-diazo 2H-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 2H-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 2H-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.

H-F bond insertions into α-diazo carbonyl compounds

A reaction for H-F bond insertion into α-diazo carbonyl compounds is reported. The protocol describes a simple reaction setup employing commercially available HF·pyr (Olah reagent) as the fluorine source. The method is rapid and practical, and allows access to a broad range of α-fluorinated carbonyl compounds in generally good yields.