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α-Branched amines are fundamental building blocks in a variety of natural products and pharmaceuticals. Herein is reported a unique cascade reaction that enables the preparation of α-branched amines bearing aryl or alkyl groups at the β- or γ-positions. The cascade is initiated by reduction of redox active esters to alkyl radicals. The resulting alkyl radicals are trapped by styrene derivatives, leading to benzylic radicals. The persistent 2-azaallyl radicals and benzylic radicals are proposed to undergo a radical–radical coupling leading to functionalized amine products. Evidence is provided that the role of the nickel catalyst is to promote formation of the alkyl radical from the redox active ester and not promote the C–C bond formation. The synthetic method introduced herein tolerates a variety of imines and redox active esters, allowing for efficient construction of amine building blocks. 

A unique enantioselective nickel-catalyzed vinylation of 2-azaallyl anions is advanced for the first time. This method affords diverse vinyl aryl methyl amines with high enantioselectivities, which are frequently occurring scaffolds in natural products and medications. This C–H functionalization method can also be extended to the synthesis of enantioenriched 1,3-diamine derivatives by employing suitably elaborated vinyl bromides. Key to the success of this process is the identification of a Ni/chiraphos catalyst system and a less reducing 2-azaallyl anion, all of which favor an anionic vinylation route over a background radical reaction. A telescoped gram scale synthesis and a product derivatization study confirmed the scalability and synthetic potential of this method. 

A unique C(sp 3 )–H/C(sp 3 )–H dehydrocoupling of N -benzylimines with saturated heterocycles is described. Using super electron donor (SED) 2-azaallyl anions and aryl iodides as electron acceptors, single-electron-transfer (SET) generates an aryl radical. Hydrogen atom transfer (HAT) from saturated heterocycles or toluenes to the aryl radical generates alkyl radicals or benzylic radicals, respectively. The newly formed alkyl radicals and benzylic radicals couple with the 2-azaallyl radicals with formation of new C–C bonds. Experimental evidence supports the key hydrogen-abstraction by the aryl radical, which determines the chemoselectivity of the radical–radical coupling reaction. It is noteworthy that this procedure avoids the use of traditional strong oxidants and transition metals. 

Palladium‐catalyzed allylic alkylation of 2‐aryl‐1,3‐dithianes at room temperature is described. A variety of cyclic and acyclic electrophiles successfully coupled within‐situgenerated 2‐sodio‐1,3‐dithiane nucleophiles to afford the allylated products in good to excellent yields (25 examples). Deprotection of these products leads to valuable β,γ‐unsaturated ketones. Direct synthesis of such β,γ‐unsaturated ketones via a one‐pot allylation‐oxidation protocol is also presented. Investigation into the stereochemistry of the allylation reaction revealed that the 2‐sodio‐1,3‐dithiane nucleophile behaves as a “soft” nucleophile, which underwent external attack on the π‐allyl palladium complex to provide retention of stereochemistry (double inversion pathway). Additionally, the utility of this method was demonstrated through a sequential one‐pot allylation‐Heck cyclization to produce asterogynin derivatives, which are important bioactive compounds in medicinal chemistry.

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