Gold(I)-Catalyzed Regioselective Hydroarylation of indole-Ynones: An Approach to Carbazole Derivatives

Abstract

A gold(I)-catalyzed regioselective umpolung hydroarylation of indole-ynones to dihydrocarbazoles is reported. When a vinyl group is installed at the carbonyl end, ynone umpolung arylation is achieved, followed by tandem Nazarov cyclization to polycycles, while hydroarylation/oxidation directly gives carbazoles. The reaction proceeds under mild conditions with high tolerance for diverse substituents.The carbazole motif is a common structural pattern in natural products and biologically active molecules. It also acts as a potentially valuable precursor for various transformations and drug discovery efforts, such as carbazomycin 1, antioxidant 2, and aryl hydrocarbon receptor 3 (Scheme 1). [1][2][3] In this context, the development of efficient methods to synthesize structurally diverse carbazole derivatives for the discovery of pharmaceutical lead compounds is still being actively pursued. 4