Chirality Multiplication and Efficient Chirality Transfer in <i>e</i><i>xo</i>- and <i>e</i><i>ndo</i>-Radical Cyclization Reactions of 4-(4‘-Iodobutyl)quinolones

Abstract

[reaction: see text] Enantioselective radical cyclization reactions were performed in the presence of chiral complexing agent 1. The title compounds 3 yielded, depending on the 3'-substitution (R = H, Me), the corresponding endo- (4) or exo-product (5). The highest enantioselectivities (99% and 94% ee) were achieved with 2.5 equiv of complexing agent. The cyclization product trans-4 was obtained in 55% ee in the presence of only 0.1 equiv of complexing agent.