Deoxygenative Deuteration of Carboxylic Acids with D2O

We report a general, practical, and scalable means of preparing deuterated aldehydes from aromatic and aliphatic carboxylic acids with D₂O as an inexpensive deuterium source. The use of Ph₃P as an O‐atom transfer reagent can facilitate the deoxygenation of aromatic acids, while Ph₂POEt is a better O‐atom transfer reagent for aliphatic acids. The highly precise deoxygenation of complex carboxylic acids makes this protocol promising for late‐stage deoxygenative deuteration of natural product derivatives and pharmaceutical compounds.     

Palladium‐Catalyzed ortho‐Selective C?H Deuteration of Arenes: Evidence for Superior Reactivity of Weakly Coordinated Palladacycles

We disclose a protocol for the palladium‐catalyzed ortho‐selective C H deuteration of arenes. Phenylacetic acids and benzoic acids are suitable substrates for this reaction. This reaction offers a catalytic route to ortho‐deuterated phenylacetic acids and benzoic acids and demonstrates the sharp difference in reactivity of palladacycle intermediates held together by weak and strong coordination.