Abstract
A photoinduced palladium-catalyzed cascade reaction involving remote C(sp3)–H functionalization and intramolecular Tsuji–Trost annulation is developed. The
reaction is proposed to proceed through a sequence involving the amidyl radical generation,
1,5-HAT-mediated alkyl radical formation, and subsequent difunctionalization of 1,3-dienes.
Without the use of exogeneous photosensitizers and external oxidants, the reaction
provided an efficient approach to multi-substituted chiral piperidines in high yields,
employing readily available chiral amino acid derivatives and 1,3-dienes as the substrates.
In most cases, the syn/anti ratio of the product could be further improved by treatment with catalytic amount
of iron salt.
Key words
excited-state Pd catalysis - chiral piperidines - amino acids - 1,3-dienes - Tsuji–Trost
annulation
