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Catalysis by excited‐state palladium has emerged as an active area of research, but controlling the enantioselectivity remains a challenge. Herein, we report the use of synergistic Pd/Cu catalysis to accomplish the first three‐component photochemical 1,4‐bisalkylation reactions of 1,3‐butadiene. Consequently, α‐amino acid esters bearing quaternary stereocenters were expeditiously synthesized from three simple starting materials: an alkyl bromide, butadiene, and an aldimine ester. Experimental and computational investigation of the reaction mechanism confirmed a radical pathway involving catalysis by an excited‐state palladium species. The stereochemistry is mainly controlled by the chiral Cu catalyst. [ABSTRACT FROM AUTHOR]

As a fundamental and synthetically useful C−C bond formation reaction, the aldol reaction is one of the most versatile transformations in organic synthesis. However, despite extensive research on asymmetric versions of the reaction, a unified method for stereoselective access to the complementary syn and anti diastereomeric products remains to be developed. In this study, we developed a synergistic palladium/chiral Lewis base system that overcomes the inherent diastereoselectivity bias of aldol reactions and, as a result, allowed us to achieve the first diastereodivergent coupling reactions of alkoxyallenes with pentafluorophenol esters. Computational studies suggest a mechanism involving an intermolecular protonative hydropalladation pathway rather than a palladium‐hydride migratory insertion pathway. The origin of the stereochemistry for this synergistic catalysis system is rationalized by DFT calculations. [ABSTRACT FROM AUTHOR]

Keywords: Excited-State Palladium; Photochemical; Radical Coupling; Synergistic Catalysis; Unnatural Amino Acids EN Excited-State Palladium Photochemical Radical Coupling Synergistic Catalysis Unnatural Amino Acids 1 1 1 09/28/22 20221004 NES 221004 B Photocatalysis b . The enantioselective three-component photochemical 1,4-bisalkylation of 1,3-butadiene with Pd/Cu catalysis is reported by Qinglong Zhang, Weiwei Zi, and Huimin Yu in their Research Article (e202208411). Frontispiece: Enantioselective Three-Component Photochemical 1,4-Bisalkylation of 1,3-Butadiene with Pd/Cu Catalysis. [Extracted from the article]

Push ‐ over: A novel domino reaction of activated conjugated dienes and methyleneindolinones incorporates a phosphine ‐ catalyzed intermolecular Rauhut–Currier to form two CC bonds and a quaternary carbon center. This method can be used to synthesize spirocyclopenteneoxindoles skeletons, which are potential building blocks for biologically active compounds. [ABSTRACT FROM AUTHOR]