Palladium-Catalyzed Carbocyclizations of Unactivated Alkyl Bromides with Alkenes Involving Auto-tandem Catalysis.

The development of a general catalytic system for the palladium-catalyzed carbocyclization of unactivated alkyl bromides with alkenes is described. This approach uses a commercially available bisphosphine ligand and avoids the use of carbon monoxide atmosphere present in prior studies involving alkyl iodides. Detailed mechanistic studies of the transformation are performed, which are consistent with auto-tandem catalysis involving atom-transfer radical cyclization followed by catalytic dehydrohalogenation.

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

A catalytic C-H alkylation using unactivated alkyl halides and a variety of arenes and heteroarenes is described. This ring-forming process is successful with a variety of unactivated primary and secondary alkyl halides, including those with β-hydrogens. In contrast to standard polar or radical cyclizations of aromatic systems, electronic activation of the substrate is not required.