Catalyst-Controlled Chembselective Arylation of 2-Aminobenzimidazoles

摘要

Transition-metal-catalyzed heteroatom arylation reactions are emerging as valuable tools in organic synthesis, fuelled by the identification of more efficient catalyst systems with increased substrate scopes.The synthetic utility of these transformations is increased if catalysts are both highly reactive and selective. This is particularly important for substrates with multiple heteroatom sites capable of undergoing reaction. Furthermore, the development of complementary sets of catalysts or conditions for the selective arylation of substrates possessing multiple nucleophilic sites enables the rapid, protecting group-free generation of molecular complexity with minimal synthetic manipulations. In this context, we have developed sets of procedures for the Pd- and Cu-catalyzed chemoselective arylation of aminobenzami-des, 5-aminoindole, 4-(2-aminoethyl)aniline,amino alcohols, oxindoles, and aminophenols.