We report the development of ureas as sterically undemanding pro-ligands for Pd catalysis. N -Arylureas outperform phosphine ligands for the Pd-catalyzed heteroannulation of N -tosyl- o -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.

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. By using PAd2nBu as a ligand, we have achieved regioselective heteroannulation of o-bromoanilines with branched 1,3-dienes through ligand control. This enables regiodivergent access to 3-substituted indolines, showcasing excellent regioselectivity and reactivity across a range of functionalized substrates. To gain further insights into the origin of selectivity control, we employed a data-driven strategy, developing a linear regression model using calculated parameters for phosphorus ligands. This model identified four key parameters governing regioselectivity in this transformation, paving the way for future methodology development. Additionally, density functional theory calculations elucidated key selectivity-determining transition structures along the reaction pathway, corroborating our experimental observations and establishing a solid foundation for future advancements in regioselective olefin difunctionalization reactions.