Catalytic asymmetric dicarbofunctionalization of tethered alkenes has emerged as a promising tool for producing chiral cyclic molecules; however, it typically relies on aryl-tethered alkenes to form benzene-fused compounds. Herein, we report an enantioselective cross-electrophile divinylation reaction of nonaromatic substrates, 2-bromo-1,6-dienes. The approach thus offers a route to new chiral cyclic architectures, which are key structural motifs found in various biologically active compounds. The reaction proceeds under mild conditions, and the use of chiral t-Bu-pmrox and 3,5-difluoro-pyrox ligands resulted in the formation of divinylated products with high chemo-, regio-, and enantioselectivity. The method is applicable for the incorporation of chiral hetero-and carbocycles into complex molecules.
Asymmetric cross-electrophile difunctionalization of
tethered alkenes
has become a powerful tool for the production of chiral cyclic scaffolds;
however, the current studies all focus on carbocyclization reactions.
Herein, we report an N-cyclization–alkylation
reaction and thus showcase the potential of heterocyclization for
accessing new enantioenriched cyclic architectures. This work establishes
a new approach for enantioselective aza-Heck cyclization/cross-coupling
sequence, which remains a long-standing unsolved challenge for the
synthetic community. The reaction proceeds with primary, secondary,
and a few tertiary alkyl iodides, and the use of newly defined ligands
gave highly enantioenriched pyrrolines with improved molecular diversity
under mild conditions. The presence of imine functionality allows
for further structural variations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.