Single-step construction of an acetoxypyrroloindole skeleton via tandem iodocyclization/acetoxylation of indoles

A method for the synthesis of C3a acetoxy hexahydropyrrolo[2,3-b]indole derivatives via a PhI(OAc)₂/ⁿBu₄NI mediated tandem iodocyclization/acetoxylation has been developed. The newly developed synthetic strategy features the single-step assembly of various C3a acetoxylated tetrahydropyrrole-, tetrahydrofuran-, and lactone-fused indolines under mild reaction conditions, which enabled efficient asymmetric synthesis of (-)-protubonine B.

One-step assembly of alkoxypyrroloindolines via iodine-catalyzed alkoxycyclization of indole derivatives

Herein we report an iodine-catalyzed alkoxycyclization of tryptamine derivatives under mild reaction conditions. This method distinguished itself by providing a catalytic, one-step assembly of diversely functionalized C3a-alkoxypyrroloindolines as well as dihydrofuran and lactone fused indolines. Mechanistic studies suggest that an ionic pathway is operative and this probably accounts for the diastereospecificity of all isolated cycloadducts.

Selenium-Iodine Cooperative Catalyst for Chlorocyclization of Tryptamine Derivatives

Chlorocyclization of tryptamine derivatives has been developed with the use of a diphenyl diselenide-iodine cooperative catalyst. Various tryptamine derivatives can be smoothly converted to the corresponding C3a-chlorohexahydropyrrolo[2,3-b]indoles. Additionally, we demonstrate the formal total syntheses of (-)-psychotriasine and (-)-acetylardeemin by introducing nucleophiles to the C3a position of the products.