Enantioselective catalytic remote perfluoroalkylation of α-branched enals driven by light

Herein, we report a photochemical organocatalytic method for the asymmetric introduction of perfluoroalkyl fragments (including the valuable trifluoromethyl moiety) at the remote gamma-position of alpha-branched enals. The chemistry exploits the ability of extended enamines (dienamines) to form photoactive electron donor-acceptor (EDA) complexes with perfluoroalkyl iodides, which under blue light irradiation generate radicals through an electron transfer mechanism. The use of a chiral organocatalyst, derived from cis-4-hydroxy-l-proline, secures a consistently high stereocontrol while inferring complete site selectivity for the more distal gamma position of the dienamines.

Automated summary

Here, a photochemical organocatalytic method for asymmetric introduction of perfluoroalkyl fragments at the gamma-position of alpha-branched enals is reported. The method utilizes the ability of extended enamines to form photoactive electron donor-acceptor complexes with perfluoroalkyl iodides, generating radicals through an electron transfer mechanism under blue light irradiation. The use of a chiral organocatalyst derived from cis-4-hydroxy-l-proline ensures high stereocontrol and complete site selectivity for the more distal gamma position of the dienamines.