Asymmetric catalytic 1,6-conjugate addition/aromatization of para-quinone methides: Enantioselective introduction of functionalized diarylmethine stereogenic centers
It′s just a phase: The title reaction sequence of para-quinone methides (p-QMs) has been developed with malonates under phase-transfer catalysis. The reaction also offers an alternative route to asymmetric construction of diarylmethine stereocenters in ex
Enantioselective Construction of Single and Vicinal All-Carbon Quaternary Stereocenters through Ion-Pair-Catalyzed 1,6-Conjugate Addition
An asymmetric 1,6-conjugate addition to presynthesized δ-aryl-δ-cyano-disubstituted para-quinone methides through bifunctional phosphonium-amide-promoted ion-pair catalysis for acyclic all-carbon quaternary stereocenter construction has been described. Both acyclic and cyclic 1,3-dicarbonyls participate in the asymmetric alkylation reaction, furnishing a wide array of diarylmethanes bearing a single acyclic quaternary carbon stereocenter or vicinal cyclic and acyclic quaternary carbon stereocenters with high efficiency and excellent stereoselectivity. Computational studies elucidate the origin of the enantioselectivity.
Zhu, Yasheng,Wang, Hongliang,Wang, Gang,Wang, Zehua,Liu, Zhaopeng,Liu, Lei
supporting information
p. 7248 - 7253
(2021/09/14)
Highly enantioselective introduction of bis(alkoxycarbonyl)methyl group into the 2-position of piperidine skeleton
Copper ion catalyzed carbon-carbon bond forming reaction of N-acyliminium ions with diaryl malonates was achieved with high enantioselectivity. The key intermediates in the method were 2-methoxy-3,4-didehydropiperidines, which were easily prepared through