Sonogashira‐type cross‐couplings are one of the most significant alkynylations in organic chemistry. One of the first palladium‐catalyzed intramolecular Heck/Sonogashira reactions of alkenes with terminal alkynes is now reported. With this method, a variety of uniquely substituted chiral benzene‐fused heterocycles bearing a propargyl‐substituted all‐carbon quaternary stereocenter were obtained in a straightforward, high‐yielding, and highly stereoselective manner under mild conditions. Salient features of this process include the use of readily available substrates, high selectivities, a broad substrate scope as well as versatile product functionalizations.
A Pd/Xu-Phos-catalyzed asymmetric
Heck/Suzuki domino reaction has
been developed that shows high functional group tolerance and enables
coupling with various aryl/alkenyl borates. A series of chiral disubstituted
dihydroisoquinolinones could be obtained in good yields and excellent
enantioselectivities.
Polycyclic polyprenylated acylphloroglucinols
(PPAPs) share a common
bicyclo[3.3.1]alkenone core structure and attract numerous attention
from synthetic organic chemists due to their fascinating biological
properties and associated synthetic challenges. We present herein
that Pd-phosphoramidite catalysts promote the enantioselective dearomative
allylic annulation reaction between allyl desoxyhumulones and allylic
dicarbonates, affording PPAPs analogues in good yields and enantioselectivities.
The reaction likely proceeds through two-step dearomative allylation
by Pd, and the C-allylation pathway is the dominant
mechanistic model.
γ‐Butenolide and γ‐butyrolactone scaffolds are two types of important core structures in numerous natural products and bioactive targets. However, methods to construct the chiral quaternary arylated γ‐butenolide are rarely explored. We herein report an efficient Pd‐catalyzed enantioselective γ‐arylation of β,γ‐unsaturated butenolides with aryl bromides, which shows high γ‐selectivity, good functional group tolerance and excellent enantioselectivity. Notably, this protocol also allows for facile construction of tricyclic tetrahydroindolines and tetrahydroisoquinolinones in one step. DFT calculations are consistent with the experimental results, suggesting that the γ‐arylation is favoured over the α‐arylation. Finally, this method is applied to the rapid synthesis of natural product (R)‐(+)‐boivinianin A.
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.