Ligand control of regioselectivity in palladium-catalyzed heteroannulation reactions of 1,3-Dienes.

Olefin carbofunctionalization reactions are indispensable tools for constructing diverse, functionalized scaffolds from simple starting materials. However, achieving precise control over regioselectivity in intermolecular reactions remains a formidable challenge. Here, we demonstrate that using PAdBu as a ligand enables regioselective heteroannulation of o-bromoanilines with branched 1,3-dienes through ligand control.

Dienes as Versatile Substrates for Transition Metal-Catalyzed Reactions.

Dienes have been of great interest to synthetic chemists as valuable substrates due to their abundance and ease of synthesis. Their unique stereoelectronic properties enable broad reactivity with a wide range of transition metals to construct molecular complexity facilitating synthesis of biologically active compounds. In addition, structural diene variation can result in substrate-controlled reactions, providing valuable mechanistic insights into reactivity and selectivity patterns.

Pd-Catalyzed Heteroannulation Using -Arylureas as a Sterically Undemanding Ligand Platform.

We report the development of ureas as sterically undemanding pro-ligands for Pd catalysis. -Arylureas outperform phosphine ligands for the Pd-catalyzed heteroannulation of -tosyl--bromoanilines and 1,3-dienes, engaging diverse coupling partners for the preparation of 2-subsituted indolines, including sterically demanding substrates that have not previously been tolerated. Experimental and computational studies on model Pd-urea and Pd-ureate complexes are consistent with monodentate binding through the nonsubstituted nitrogen, which is uncommon for metal-ureate complexes.