Access to tetrahydrocarbazoles and pyrrolo[3,4-b]carbazoles through sequential reactions of triazoles and indoles

Tetrahydrocarbazoles and pyrrolo[3,4-b]carbazoles could be synthesized conveniently through sequential reactions of ester-tethered 1-sulfonyl-1,2,3-triazoles and indoles. The reaction conditions were mild and the procedures were quite simple. Moreover, the key intermediate α,β-unsaturated imine acted as a [2C] synthon in the [4 + 2] cycloaddition reaction, and the imino group could be used as a nucleophile to construct the fourth ring.

Rh(II)-catalyzed Denitrogenative Cascade of 1,2,3-Triazolyl Propiolates and Indoles: Access to Butenolide Tethered Homotryptamines

An efficient Rh(II)-catalyzed denitrogenative reaction of indoles with 1,2,3-triazolyl propiolates has been developed. This methodology provides facile access to butenolide tethered homotryptamines in good to excellent yields under operationally simple conditions and features a broad substrate scope. Overall, the reaction sequence involves the formation of three new bonds (two C-C and one C-O) in a nucleophilic cascade manner. Additionally, an intramolecular rearrangement of these derivatives to thermodynamically more stable butenolides is also demonstrated.

Synthesis of α-cyano sulfone via thermal rearrangement of 1,4-disubstituted triazole mediated by carbene and radical species

α-Cyano sulfone is produced conveniently from 1,4-disubstituted triazole, which involves carbene, ketenimine and radical species as the key intermediates.

Synthesis of α-aminoketones from N-sulfonyl-1,2,3-triazoles via N-sulfinyl imines generated by intramolecular oxygen transfer

A sulfinyl imine was generated by intramolecular oxygen transfer of an α-iminocarbene, which led to an α-aminoketone via nucleophilic addition and oxidation.

Rhodium(ii)-catalyzed divergent intramolecular tandem cyclization of N- or O-tethered cyclohexa-2,5-dienones with 1-sulfonyl-1,2,3-triazole: synthesis of cyclopropa[cd]indole and benzofuran derivatives

A novel rhodium(ii)-catalyzed divergent intramolecular tandem cyclization of N- or O-tethered cyclohexa-2,5-dienones and 1-sulfonyl-1,2,3-triazole is disclosed, affording cyclopropa[cd]indole and benzofuran derivatives in moderate to good yields.