Cobalt-catalyzed oxidative isocyanide insertion to amine-based bisnucleophiles: diverse synthesis of substituted 2-aminobenzimidazoles, 2-aminobenzothiazoles, and 2-aminobenzoxazoles.

ABSTRACT

Cobalt catalysis Synthesis of substituted 2-aminobenzimidazoles, 2-aminobenzothiazoles, and 2-aminobenzoxazoles was achieved by using cobalt(II) acetate catalyzed isocyanide insertion to o-diaminobenzene, 2-aminobenzenethiol, and 2-aminophenol derivatives in 1,4-dioxane (see scheme). It was found that the reaction proceeded efficiently to give the desired products in up to 95 % isolated yields by C-N and C-S (O, N) formation in a single step.