Photocatalytic Asymmetric Acyl Radical Truce–Smiles Rearrangement for the Synthesis of Enantioenriched α‐Aryl Amides
Wei‐Yang Ma, Matteo Leone, Étienne Derat, Pascal Retailleau, Chada Raji Reddy, Luc Neuville, Géraldine Masson
Abstract
The radical Truce-Smiles rearrangement is a straightforward strategy for incorporating aryl groups into organic molecules for which asymmetric processes remains rare. By employing a readily available and non-expensive chiral auxiliary, we developed a highly efficient asymmetric photocatalytic acyl and alkyl radical Truce-Smiles rearrangement of α-substituted acrylamides using tetrabutylammonium decatungstate (TBADT) as a hydrogen atom-transfer photocatalyst, along with aldehydes or C-H containing precursors. The rearranged products exhibited excellent diastereoselectivities (7 : 1 to >98 : 2 d.r.) and chiral auxiliary was easily removed. Mechanistic studies allowed understanding the transformation in which density functional theory (DFT) calculations provided insights into the stereochemistry-determining step.