Cobalt-Catalyzed Reductive Carboxylation of Aldehydes/Ketones for the Synthesis of α-Arylalkanoic Acids.

α-Arylalkanoic acids are among the most extensively used classes of nonsteroidal anti-inflammatory drugs (NSAIDs) in clinical practice. Their significant role in medicinal chemistry has attracted sustained research interest over the past decades. In this paper, an efficient one-pot protocol for the synthesis of α-arylalkanoic acids using readily available aldehydes/ketones and CO2 as the starting materials was established. This protocol contains a sequence of Pudovik reaction, phospha-Brook rearrangement and cobalt-catalyzed carboxylation. The plausible mechanism of this reaction was investigated.