Enantioselective Formal α-Methylation and α-Benzylation of Aldehydes by Means of Photo-organocatalysis.
Detailed herein is the photochemical organocatalytic enantioselective α-alkylation of aldehydes with (phenylsulfonyl)alkyl iodides. The chemistry relies on the direct photoexcitation of enamines to trigger the formation of reactive carbon-centered radicals from iodosulfones, while the ground-state chiral enamines provide effective stereochemical control over the radical trapping process. The phenylsulfonyl moiety, acting as a redox auxiliary group, facilitates the generation of radicals. In addition, it can eventually be removed under mild reducing conditions to reveal methyl and benzyl groups.
ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology, Avenida Països Catalans 16, 43007, Tarragona, Spain.
Giacomo
G
Filippini
ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology, Avenida Països Catalans 16, 43007, Tarragona, Spain.
Mattia
M
Silvi
ICREA, Passeig Lluís Companys 23, 08010, Barcelona, Spain.|ICIQ-Institute of Chemical Research of Catalonia, The Barcelona Institute of Science and Technology, Avenida Països Catalans 16, 43007, Tarragona, Spain.
Paolo
0000-0001-8722-4602
P
Melchiorre
enamines; organocatalysis; photochemistry; radicals; reaction mechanisms