Synthesis of β,γ‐Unsaturated Acids from Allenes and Carbon Dioxide

Hidden talent : Often perceived to be too thermodynamically and kinetically inert to be a useful chemical feedstock, carbon dioxide adds to allenes under exceptionally mild reductive conditions in the presence of a palladium pincer complex to give β,γ‐unsaturated carboxylic acids (see scheme). This transformation is discussed in the context of the requirements for CO₂ fixation. DMF=N,N‐dimethylformamide, Tf=trifluoromethanesulfonyl.