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-gem-dihalovinylanilines. Optimal conditions used a Pd(OAc)(2)/S-Phos catalyst in the presence of K(3)PO(4).H(2)O 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 %). [reaction: see text]