Iron-Photocatalyzed Decarboxylative Alkylation of Carboxylic Acids with Morita–Baylis–Hillman Acetates

We present an iron-photocatalyzed decarboxylative alkylation strategy involving carboxylic acids and Morita–Baylis–Hillman (MBH) acetates to synthesize E-type tri- and tetrasubstituted alkenes with moderate to excellent stereoselectivity (E/Z ratio up to >19:1). This method is applicable to a broad range of structurally diverse primary, secondary, and tertiary alkyl carboxylic acids, as well as complex pharmaceutical and natural carboxylic acids, achieving efficient alkylation of various MBH acetates under mild conditions (>60 examples, with yields up to 96%). This approach offers a powerful strategy for streamlined alkylation.