Direct amidation of acid fluorides using germanium amides.

Amide functional groups are an essential linkage that are found in peptides, proteins, and pharmaceuticals and new methods are constantly being sought for their formation. Here, a new method for their preparation is presented where germanium amides Ph3GeNR2 convert acid fluorides directly to amides. These germanium amides serve to abstract the fluorine atom of the acid fluoride and transfer their amide group -NR2 to the carbonyl carbon, and so function as amidation reagents.

Transition metal-free hydrodefluorination of acid fluorides and organofluorines by Ph3GeH promoted by catalytic [Ph3C][B(C6F5)4].

It has been shown that the germane Ph3GeH converts aryl and aliphatic acid fluorides directly to their corresponding aldehydes without over-reduction via the conversion of Ph3GeH to the germylium cation [Ph3Ge]+ by a catalytic amount of the tritylium salt [Ph3C][B(C6F5)4]. Here, no transition metal catalyst is required and there is no decarbonylation of the acid fluoride, which are advantages over existing methods. The fluorine atoms can also be abstracted from organofluorine compounds using this method.