Efficient synthesis of 2-substituted indoles based on palladium(II) acetate/tri-tert-butylphosphine-catalyzed alkynylation/amination of 1,2-dihalobenzenes

A simple, efficient palladium(II) acetate/tri-tert-butylphosphine-catalyzed indole synthesis from o-alkynylhalobenzenes, readily available from 1,2-dihalobenzenes, has been achieved in good to excellent yields. A one-pot, Pd(OAc)(2)/t-Bu3P-catalyzed sequential reaction from 1-chloro-2-iodobenzene, phenylacetylene and amines has also been achieved in good yields.