Transition Metal-catalyzed Bond-forming Reactions at the C-H Bond of Heteroaromatic Compounds

抄録

Recent progress in the C-H coupling reactions of heteroaromatic compounds in our group is summarized. Coupling of thiophene derivatives occurs in the presence of a nickel or palladium catalyst with a base as an additive. Lithium t-butoxide and several magnesium amides are effective for the coupling reaction of aryl chlorides, bromides, and iodides. Coupling at the C-H bond of thiophene with thienyl halides also occurs smoothly forming a thiophene-thiophene bond. The reaction is successfully applied to the polymerization of 2-halo-3-substituted thiophenes leading to highly regioregular head-to-tail-type poly(3-substituted thiophene)s. The reaction of thiazole at the C-H bond (2-position) with several secondary amines induces C-H, N-H coupling with a copper catalyst.