Aminoguanidine-Catalyzed Reductive Cyclization of o-Phenylenediamines with CO2 in the Presence of Triethoxysilane

摘要

An inexpensive and efficient aminoguanidinecatalyzed reductive cyclization of o-phenylenediamines with CO2 in the presence of triethoxysilane is described. Various functionalized benzimidazoles, benzoxazole, and benzothiazole were synthesized in high yields. Mechanistic studies indicate that formic acid as a cocatalyst promotes the cyclization reaction.

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