Decarboxylative Alkylation of Morita-Baylis-Hillman Acetates with Aliphatic Acids via Photochemical Iron-Mediated Ligand-to-Metal Charge Transfer.

Carboxylic acids are bench-stable and readily available chemical feedstocks that function as optimal and fundamental synthetic platforms for the construction of C(sp)-C(sp) bonds via decarboxylation processes. We present a novel and practical protocol for the decarboxylative alkylation of Morita-Baylis-Hillman acetates with various carboxylic acids via a photoinduced iron-mediated ligand-to-metal charge transfer (LMCT) process under redox-neutral conditions. This method exhibits remarkable tolerance to a wide array of carboxylic acids, including primary, secondary, and tertiary carboxylic acids, obviating the requirement for preactivated radical precursors. The preliminary mechanistic analyses indicate that a radical pathway is involved in this catalytic transformation.