Recent Advances in the Catalytic Umpolung Carboxylation of Allylic Alcohol Derivatives with Carbon Dioxide
Yong You, Tsuyoshi Mita
Abstract
Abstract Allylic alcohols and their derivatives (e. g. halides, acetates, and pivalates) are readily available organic compounds that are frequently employed in organic synthesis, and especially in Tsuji‐Trost‐type allylic substitution reactions. These allylic substrates add oxidatively to transition metals such as Pd to form π ‐allyl metal species, which can act as suitable electrophiles for several nucleophilic counterparts. However, under reductive conditions, the π ‐allyl metal species instantly become nucleophilic and react with various electrophiles including the rather stable CO 2 , which is an abundant, inexpensive, non‐toxic, and renewable carbon source in organic synthesis. When CO 2 is incorporated in allylic compounds, synthetically useful β , γ ‐unsaturated carboxylic acid derivatives are obtained exclusively. In this review, we focus on the recent advances in such catalytic umpolung carboxylations of allyl alcohols, acetates, pivalates, and halides with CO 2 under thermal, photochemical, and electrochemical conditions.