Palladium-Catalyzed Branch-Selective Allylic C-H Amination Enabled by Nucleophile Coordination.

Regiochemical control is a central subject in the field of synthetic chemistry. Here we unveil an innovative approach for the branch-selective allylic C-H amination of α-alkenes with amine nucleophiles facilitated by phosphoramidite-palladium catalysis. A diverse array of α-alkenes has been effectively utilized to produce a variety of structurally distinct allylamines with moderate to excellent regioselectivity.

Enantioconvergent Palladium-Catalyzed Alkylation of Tertiary Allylic C-H Bonds.

Enantioconvergent catalysis enables the conversion of racemic molecules into a single enantiomer in perfect yield and is considered an ideal approach for asymmetric synthesis. Despite remarkable advances in this field, enantioconvergent transformations of inert tertiary C-H bonds remain largely unexplored due to the high bond dissociation energy and the surrounding steric repulsion that pose unparalleled constraints on bond cleavage and formation. Here, we report an enantioconvergent Pd-catalyzed alkylation of racemic tertiary allylic C-H bonds of α-alkenes, providing a unique approach to access a broad range of enantioenriched γ,δ-unsaturated carbonyl compounds featuring quaternary carbon stereocenters.

Palladium-Catalyzed Enantioselective C(sp)-H/C(sp)-H Umpolung Coupling of -Allylimine and α-Aryl Ketones.

Asymmetric functionalization of the C(sp)-H bond is an attractive yet challenging strategy to achieve versatile bond-forming events, enabling the precise assembly of molecular complexity with minimal manipulation of functional groups. Here, we report an asymmetric C(sp)-H/C(sp)-H umpolung coupling of -allylimine and coordinating α-aryl carbonyls by using chiral phosphoramidite-palladium catalysis. A wide variety of α-heteroaryl ketones and 2-acylimidazoles are nicely tolerated to open a convenient and tunable avenue for efficient synthesis of enantioenriched β-amino-γ,δ-unsaturated carbonyl derivatives with high levels of regio- and stereoselectivities, capable of providing a key intermediate for asymmetric synthesis of Focalin.

Asymmetric Photocatalytic C(sp)-H Bond Addition to α-Substituted Acrylates.

Asymmetric functionalization of inert C(sp)-H bonds is a straightforward approach to realize versatile bond-forming events, allowing the precise assembly of molecular complexity with minimal functional manipulations. Here, we describe an asymmetric photocatalytic C(sp)-H bond addition to α-substituted acrylates by using tetrabutylammonium decatungstate (TBADT) as a hydrogen atom transfer (HAT) photocatalyst and chiral phosphoric acid as a chiral proton-transfer shuttle. This protocol is supposed to occur via a radical/ionic relay process, including a TBADT-mediated HAT to cleave the inert C(sp)-H bond, a 1,4-radical addition, a back hydrogen abstraction, and an enantioselective protonation.