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 is...

Photo-NHC Catalysis: Accessing Ketone Photochemistry with Carboxylic Acid Derivatives

Excitation of carbonyl groups is one of the most widely employed activation modes in photochemistry. Many synthetically important transformations, however, are successful only with aldehydes and ketones; substrates at the carboxylic acid oxidation level remain underrepresented. We have developed a conceptually novel strategy for enabling ‘ketone-like’ photochemistry with carboxylic acid derivatives that employs an N-heterocyclic carbene (NHC) organocatalyst. Using this ‘Photo-NHC’ catalysis approach, a proof-of-concept photoenolization/Diels–Alder (PEDA) reaction between acid fluorides and trifluoroacetophenones was developed. Stoichiometric studies and TD-DFT calculations supported a mechanistic scenario in which the NHC influences the absorption wavelength and inherent photochemical reactivity of the carbonyl group during the catalytic cycle.1 Introduction2 Photo-NHC Catalysis3 Conclusions

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

The germylium cation [Ph3Ge]+converts aryl and aliphatic acid fluorides directly to their corresponding aldehydes. Hydrodefluorination of organofluorine compounds by [Ph3Ge]+was also observed.