Pd-catalyzed tandem C-N/C-C coupling of gem-dihalovinyl systems: A modular synthesis of 2-substituted indoles

2-Substituted indoles were synthesized via a Pd-catalyzed tandem C-N/Suzuki-Miyaura coupling from readily prepared ortho-gemdihalovinylanilines. Optimal conditions used a Pd(OAC)(2)/S-Phos catalyst in the presence of (K3PO4H2O)-H-. and an organoboron reagent, which included boronic acids, esters, alkyl 9-BBN derivatives, and trialkylboranes. Yields of the desired indoles were good to excellent using low catalyst loadings (typically 1 mol %).