Enantioselective Synthesis of Bicyclo[3.2.1]octadienes via Palladium‐Catalyzed Intramolecular Alkene‐Alkyne Coupling Reaction
Qiuyu Li, Jiajia Li, Jie Zhang, Shu Sen Wu, Yu Zhang, Aijun Lin, Hequan Yao
Abstract
Bicyclo[3.2.1]octadiene compounds and derivatives exist in a number of natural products and bioactive compounds. Nevertheless, catalytic enantioselective protocols for the synthesis of these skeletons have not been disclosed. Herein we reported a palladium-catalyzed asymmetric intramolecular alkene-alkyne coupling of alkyne-tethered cyclopentenes, affording a library of enantionenriched bicyclo[3.2.1]octadienes in excellent yields and enantioselectivities (mostly >99 % ee). Moreover, the products could undergo an unusual iodination-induced 1,2-acyl migration, forming iodinated bicyclo[3.2.1]octadienes with three vicinal stereocenters. The enone and isolated olefin motifs embedded in the products provide useful handles for downstream elaboration.