Stereospecific Nickel-Catalyzed Reductive Cross-Coupling of Alkyl Tosylate and Allyl Alcohol Electrophiles.

The stereospecific cross-coupling of easily accessed electrophiles holds significant promise in the construction of C-C bonds. Herein, we report a nickel-catalyzed reductive coupling of allyl alcohols with chiral, nonracemic alkyl tosylates. This cross-coupling delivers valuable allylation products with high levels of stereospecificity across a range of substrates. The catalytic system consists of a simple nickel salt in conjunction with a commercially available reductant and importantly represents a rare example of a cross-coupling involving the C-O bonds of two electrophiles.

Nickel-catalyzed, ring-forming aromatic C-H alkylations with unactivated alkyl halides.

The development of a nickel-catalyzed C-H alkylation of aromatic substrates with unactivated alkyl halides is described. This carbocyclization facilitates the synthesis of diverse fused ring systems from simple aromatic substrates and is an attractive alternative to traditional polar or radical-mediated ring formations. The present system uses unactivated primary and secondary alkyl bromides and chlorides, while avoiding the use of precious palladium catalysts and more reactive alkyl halides commonly used in related C-H alkylations.

Alkyne Hydroheteroarylation: Enantioselective Coupling of Indoles and Alkynes via Rh-Hydride Catalysis.

We report an enantioselective coupling between alkynes and indoles. A Rh-hydride catalyst isomerizes alkynes to generate a metal-allyl species that can be trapped with both aromatic and heteroaromatic nucleophiles.