Copper and palladium co-catalyzed highly regio-selective 1,2-hydroarylation of terminal 1,3-dienes

Alkene Hydrobenzylation by a Single Catalyst That Mediates Iterative Outer-Sphere Steps

Cross-coupling catalysts typically react and unite functionally distinct partners via sequential inner-sphere elementary steps: coordination, migratory insertion, reductive elimination, etc. Here, we report a single catalyst that cross-couples styrenes and benzyl bromides via iterative outer-sphere steps: metal-ligand-carbon interactions. Each partner forms a stabilized radical intermediate, yet heterocoupled products predominate. The system is redox-neutral and, thus, avoids exogenous oxidants, resulting in simple and scalable conditions. Numerous variations of alkene hydrobenzylation are made possible, including access to the privileged heterodibenzyl (1,2-diarylethane) motif and challenging quaternary carbon variants.

Iron-catalyzed hydroarylation of 1,3-dienes with indoles

An efficient iron-catalyzed hydroarylation of 1,3-dienes with indoles has been developed for the first time.

Cobalt-Catalyzed Z to E Geometrical Isomerization of 1,3-Dienes

An efficient cobalt-catalyzed geometrical isomerization of 1,3-dienes is described. In the combination of a CoCl₂ precatalyst with an amido-diphosphine-oxazoline ligand, the geometrical isomerization of E/Z mixtures of 1,3-dienes proceed in a stereoconvergent manner, affording (E) isomers in high stereoselectivity. This facile transformation features a broad substrate scope with good functional group tolerance and could be scaled up to the gram scale smoothly with a catalyst loading of 1 mol %.

Ni-Catalyzed Regioselective Hydroarylation of 1-Aryl-1,3-Butadienes with Aryl Halides

An efficient nickel-catalyzed regioselective hydroarylation of 1,3-dienes with aryl halides and a silane has been developed, affording a range of allylic arenes in good to excellent yields under mild conditions. This method exhibits broad substrate scope, and excellent functional group tolerance. Late-stage modification of complex architectures was demonstrated.

Copper-Catalyzed Highly Selective Protoboration of CF3 -Containing 1,3-Dienes

The copper-catalyzed highly selective protoboration of CF₃ -containing conjugated diene with proton source and B₂ Pin₂ has been developed. This chemistry could suppress the well-known defluorination and provide borated reagents with an intact CF₃ -group. Further studies indicated that the functional group tolerance of this chemistry is very well, and the products could be used as versatile precursors for different types of transformations. Importantly, using chiral diphosphine ligand, we have developed the first example for using such starting material to synthesis allylic boron-reagents which bearing a CF₃ -containing chiral center. Notably, the reaction mechanism was intensively studied by DFT calculations, which could reveal the reason that defluorination was inhibited.

Nickel-catalyzed alkenylboration of alkenylarenes to access homoallylic boronic esters

A practical nickel-catalyzed alkenylboration of alkenylarenes with excellent chemo- and regio-selectivity has been developed.