Pd-Catalyzed C(sp3)-C(sp2) cross-coupling of Y(CH2SiMe3)3(THF)2 with vinyl bromides and triflates

Electrochemical Asymmetric Radical Functionalization of Aldehydes Enabled by a Redox Shuttle

Aminocatalysis is a well-established tool that enables the production of enantioenriched compounds under mild conditions. Its versatility is underscored by its seamless integration with various synthetic approaches. While the combination of aminocatalysis with metal catalysis, photochemistry, and stoichiometric oxidants has been extensively explored, its synergy with electrochemical activation remains largely unexplored. Herein, we present the successful merger of electrochemistry and aminocatalysis to perform SOMO-type transformations, expanding the toolkit for asymmetric electrochemical synthesis. The methodology harnesses electricity to drive the oxidation of catalytically generated enamines, which ultimately partake in enantioselective radical processes, leading to α-alkylated aldehydes. Crucially, mechanistic studies highlight how this electrochemical strategy is enabled by the use of a redox shuttle, 4,4'-dimethoxybiphenyl, to prevent catalyst degradation and furnishing the coveted compounds in good yield and high enantioselectivity.

Construction of Successive Stereogenic Centers of ent-Kauranoid via Oxidative Dearomatization/1,2-Shift Cascade

Construction of successive stereogenic centers including an all-carbon quaternary stereogenic center of ent-kauranoid via oxidative dearomatization/1,2-shift cascade is described. The developed cascade reaction of a substrate bearing a trans-2-(p-methoxyphenyl)vinyl group as the migrating group afforded the desired product in 83% yield. The 1,2-shift in the cascade is strongly affected by the stereoelectronic effect. X-ray crystal structure of a compound bearing four successive stereogenic centers in the fused ring moiety of ent-kauranoid diterepene, which was prepared by the oxidative dearomatization/1,2-shift cascade and subsequent stereoselective transformations, is also reported.