Bulky Alkyl Substituents Enhance the Photocatalytic Activity of Pyridine-Based Donor-Acceptor Molecules in the Direct Reductive Cleavage of the C-Br Bond of Aliphatic Bromides.

We report new pyridine-based donor-acceptor (D-A) molecules that enable the direct reductive transformation of a variety of secondary and tertiary aliphatic bromides. A series of experimental and theoretical results suggested that the D-A molecules promote direct C-Br bond cleavage triggered by the excitation of the complex between the catalyst and the aliphatic bromide and that the alkyl groups significantly contribute to the stabilization of the complex, which improves the efficiency of its excitation.